Crash Bandicoot 2: Cortex Strikes Back (Japanese: クラッシュ・バンディクー2 コルテックスの逆襲!) is a platform game and the second game of the Crash Bandicoot series. It was developed by Naughty Dog for the PlayStation and released in the United States of America on the Halloween of 1997. It was also released on the PlayStation Network for download so it can be played on the PlayStation 3, PlayStation Portable and PlayStation Vita. It is the best selling Crash game of all time, with 7.58 million copies sold globally.
This sequel to the original Crash Bandicoot focuses on a bandicoot under the name of Crash Bandicoot. Crash is abducted by the main antagonist, Doctor Neo Cortex, who has apparently turned over a new leaf and is now willing to save the world. Crash is then thrust into several parts of the islands in order to gather crystals and allow Cortex to contain the power of the upcoming planetary alignment and keep the planet from being destroyed. He is joined by Coco Bandicoot, his sister, who is suspicious of Cortex's true intentions. Doctor Nitrus Brio, who has a personal vengence for Cortex, tries to convince Crash to gather gems instead of crystals in hope of destroying his arch-enemy Cortex and sends his own henchmen to stop the bandicoot's progress.
Bandipedia contains spoilers for all Crash Bandicoot related media. You have been warned!
Taking place right after the previous game's events, in which Crash Bandicoot fights Doctor Neo Cortex on top of his airship, Cortex is defeated, and the rocketsled he was standing on explodes. Cortex falls to the ground, and he lands in a mine, where he discovers a large crystal, and has a flash of inspiration. One year later, he is seen in a space station, being told by his new assistant Doctor N. Gin that to harness the Master Crystal's power, he will require an additional 25 "Slave Crystals", which are scattered across the Earth. Since Cortex does not have any "friends" left on the surface, he decides to abduct Crash (while he is searching for a spare battery for Coco's laptop) and persuades him to gather the slave crystals, telling him that he will use them to harness the power of the aligned planets and prevent Earth from certain doom.
Throughout his quest, Crash is contacted by his sister Coco, who is continuously searching into Cortex's scheme and trying to figure out what Cortex is really using the crystals for, as well as Cortex's former assistant, Doctor Nitrus Brio, who tells Crash that if he truly wants to save the world, he must collect gems instead of crystals, so that Brio may use the gems to destroy Cortex, who took credit for Brio's creation of the Evolvo-Ray. He is also Crash's primary opposing force, claiming to use all of his strength to prevent him from gathering crystals. Brio recruits Ripper Roo, who has become extremely intelligent but is still insane, to destroy Crash. Brio also creates and sends out new villains, like the sword-swinging Komodo Brothers and muscle bound Tiny Tiger, but unfortunately for him, they all fail to stop Crash. Cortex later demands Crash to hand his current amount of crystals over to N. Gin, but to his dismay he finds out the marsupial instead defeated N. Gin.
At the end, when all of the Crystals are collected, Coco reveals that Cortex actually intends to harness the force of the Crystals to turn every single creature on Earth into Cortex's mindless slaves with his new and improved Cortex Vortex, and Crash defeats Cortex once again, banishing him deep into space, but leaving his space station operational. After Crash gathers all 42 gems, N. Brio uses the gems to destroy Cortex's space station with a laser beam, leaving the station in space until it crashes into a mysterious temple on earth.
Crash Bandicoot 2's gameplay is largely similar to that of the original. However, there are some differences. Players make their way through a limited environment whilst breaking crates, each of which containing some kind of bonus. Breaking all of a level's crates earns the player that level's clear gem. The player can also collect additional clear and colored gems by finding and touching them. Colored gems activate secret areas. If the player collects all of the gems in the game, the secret ending is activated.
Crash has several moves: jump, spin attack, body slam, slide, duck, crawl, and an extra-high jump performed by sliding or ducking and then jumping. There are also several difficult glitched moves that can be performed at any time. Stepping on a question-mark platform/trap door takes Crash to a bonus level. Going to special locations, where something is somehow out of place, brings Crash to one of five secret levels.
Also, if the player manages to reach a certain point in some levels without losing a single life, the player can hop onto a platform with a skull and crossbones logo on it. This takes Crash to another portion in the level of the main path and contains boxes and other secrets one might notice not being found on the main path. This marked the first appearance of the death route.
Warp Room & Levels
Crash Bandicoot 2 introduces the Warp Room system. Unlike the original, where levels are played in a specific order, the warp room allows the player to play one of the five levels present in the room in any order. To complete a level, the player has to fetch the crystal and reach the end of the level. When all 5 crystals have been collected, the player can move to the next warp room. There are five main warp rooms, twenty-five main levels, five boss arenas, a sixth secret warp room with three secret entrances and two extra levels. Boss fights are in bold.
|Warp Room||Level Type||Level||Items||Boxes||Enemies/Obstacles|
1, first Island
|Jungle||1. Turtle Woods||Crystal, Clear Gem, Blue Gem||62||Armadillo; Spike Turtle; Vulture; Ostrich|
|Snow||2. Snow Go||Crystal, Clear Gem, Red Gem||74||Penguin; Fur Seal; Pillar 1; Echidna|
|Stream||3. Hang Eight||Crystal, 2 Clear Gems||74||Fish; Venus Fly Trap; Water Mine; Whirlpool; Hippo|
|Jungle||4. The Pits||Crystal, 1 Clear Gem||53||Armadillo; Spike Turtle; Blade Turtle; Vulture|
|Chase||5. Crash Dash||Crystal, 1 Clear Gem||44||Boulder; Electric Fence; Spring Mine|
|Boss/Waterfall||Ripper Roo||N/A||N/A||Ripper Roo, TNT platforms/Nitro platforms Ripper Roo creates via bouncing.|
2, second Island
|Snow||6. Snow Biz||Crystal, 1 Clear Gem||124||Penguin; Fur Seal, Pillar 1; Echidna; Icicle, Rolling Stone|
|Stream||7. Air Crash||Crystal, 2 Clear Gems||102||Fish; Venus Fly Trap; Water Mine; Whirlpool; Hippo|
|Polar||8. Bear It||Crystal, 1 Clear Gem||48||Totem Pole; Fur Seal; Orca|
|Chase||9. Crash Crush||Crystal, 1 Clear Gem||57||Boulder; Electric Fence; Spring Mine|
|Sewer||10. The Eel Deal||Crystal, Clear Gem, Green Gem||79||Eel; Fan; Rolling Toxic Waste Can; Spike Rat; Scrubbing Bubbletron; Hovering Spike-O-Tron|
|Boss/Circus Tent||Komodo Brothers||N/A||N/A||Moe; Swords; Joe|
3, third Island, Cortex Power
|Stream||11. Plant Food||Crystal, Clear Gem, Yellow Gem||53||Venus Fly Trap; Water Mine; Whirlpool; Hippo|
|Sewer||12. Sewer or Later||Crystal, 2 Clear Gems||57||Eel; Fan; Flamethrowing Scientist; Rolling Toxic Waste Can; Spike Rat; Scrubbing Bubbletron|
|Polar||13. Bear Down||Crystal, 1 Clear Gem||42||Totem Pole; Fur Seal; Orca; Lifters|
|Ruins||14. Road to Ruin||Crystal, 2 Clear Gems||89||Jumping Monkey; Log Throwing Monkey; Spike Lizard; Possum|
|Chase/Polar||15. Un-Bearable||Crystal, 1 Clear Gem||58||Giant Bear; Electric Fence; Wood Fence; Spring Mine; Lizard; Spike Turtle; Blade Turtle; Hunter|
|Boss/Futuristic Space Lab||Tiny Tiger||N/A||N/A||Tiny Tiger; falling platforms|
4, third Island, Cortex Castle
|Sewer||16. Hangin' Out||Crystal, 1 Clear Gem||93||Eel, Fan, Flamethrowining Scientist; Rolling Toxic Waste Can; Spike Rat; Scrubbing Bubbletron; Hovering Spike-O-Tron|
|Mountain||17. Diggin' It||Crystal, 2 Clear Gems||95||Spring Mines 2; Spitter Plant; Tiki; Bees; Lumberjack; Electric Fence|
|Snow||18. Cold Hard Crash||Crystal, 2 Clear Gems||155||Penguin; Fur Seal 1; Pillar 1; Echidna; Icicle|
|Ruins||19. Ruination||Crystal, 2 Clear Gems||84||Jumping Monkey; Log Throwing Monkey; Lizard 1 Possum|
|Mountain||20. Bee-Having||Crystal, Clear Gem, Purple Gem||92||Spitter Plant; Lumberjack; Tiki; Bees; Electric Fence; Spring Mines 2; Armadillo 3; Hunter|
|Boss/Space Port||Dr. N. Gin||N/A||N/A||Dr. N. Gin, Lasers, Missiles|
5, Cortex Vortex
|Machinery||21. Piston It Away||Crystal, 2 Clear Gems||69||4-Legged Robot; Electric Robot; Pillar 2; Lab Assistant 1|
|Jet Pack||22. Rock It||Crystal, 1 Clear Gem||39||Lab Assistant 2; Laser; Wire; Fireball|
|Jungle (Night)||23. Night Fight||Crystal, 2 Clear Gems||46||Holoprojector; Frilled Lizard; Possum|
|Jet Pack||24. Pack Attack||Crystal, 1 Clear Gem||46||Lab Assistant 2; Laser; Wire; Fireball|
|Machinery||25. Spaced Out||Crystal, 2 Clear Gems||60||4-Legged Robot; Electric Robot; Lab Assistant 1; Pillar|
|Boss/Space||Dr. Neo Cortex||N/A||N/A||Dr. Neo Cortex; asteroids; mines|
Chamber 6 (Secret Warp Room)
|Stream||7. Air Crash (Secret Entrance)||N/A||102||Fish; Venus Fly Trap; Water Mine; Whirlpool; Hippo|
|Snow||2. Snow Go (Secret Entrance)||N/A||74||Penguin; Fur Seal; Echidna; Pillar 1|
|Ruins||14. Road to Ruin (Secret Entrance)||N/A||89||Statue|
|Polar||26. Totally Bear||Clear Gem||40||Totem Pole; Parka Lab Assistant; Orca|
|Jungle (Night)||27. Totally Fly||Clear Gem||44||Holoprojector; Possum; Frilled Lizard|
These are the main jungle-themed levels of the game. There are other levels that appear in jungle like settings, like the chase levels in snowy jungles, and the night levels in a dark jungle setting.
These are the main snow-themed levels of the game. There are three of them. There are also many other levels that take place in snow, like the chase levels and the Polar levels, but these are the ones where the main theme is snow and ice. Most of the enemies consist of penguins, seals and echidnas. Parts of these levels contain ice, in which when Crash walks on it, he gently slides while standing. The first part of these levels is 3D walking forward gameplay, which second part is side-scrolling, and the final part returns to 3D gameplay, similar to Gone Tomorrow of Crash Bandicoot 3: Warped.
These are the stream-themed levels in the game. There are three of them. These levels are just like the ones from the first game, except with more enemies and detail. They also introduce the Jet Board for the first time, which Crash can ride through the stream.
These levels feature Crash getting chased by a giant snowball or a polar bear. There are three of them. These levels are quite like the chase levels of the first game, except in a mountainous region.
In these levels, Crash rides Polar in a snowy-themed region. There are 4 of them (but one of them also requires Crash to get chased by a huge bear). He rides Polar in a similar fashion to the levels with the hog in the first Crash game and the levels in ancient China with Pura in the next game. Some of the ice elements of the snow levels have been incorporated in some of these levels.
- Bear It (Level 8)
- Bear Down (Level 13)
- Un-Bearable (Level 15)*
- Totally Bear (Level 26)**
- *This is also a Chase level. But only the last quarter of it appears Crash riding Polar while getting chased by a giant polar bear.
- **Secret level 1 of 2
These are the sewer-themed levels. In them, Crash goes through a sewer in which he must avoid Scrubbing Bubbletrons, Lab Assistants, flying robots and mutated rats. On some of these levels, there is a part where Crash hangs from metal meshes. This was reused in the Arabian levels of Crash Bandicoot 3: Warped and a few levels in Crash Bandicoot: The Wrath of Cortex, Crash Bandicoot: The Huge Adventure, and Crash Bandicoot 2: N-Tranced.
These levels take place in ancient ruins, with thin platforms that break often. There are only two levels. They are quite similar to the temple levels from Crash Bandicoot.
These levels take place in a mountainous region, filled with bees, spitter plants, and sledgehammer lab assistants. In these levels, Crash can dig into some parts of the ground to avoid the three enemies and more (except for nitro crates). There are only two levels.
These levels are futuristic-themed and are played inside Cortex's Cortex Vortex. There are only two levels. Crash faces robots and machines while making his way through the levels.
In these levels, Crash flies around in a jet pack. There are only two levels.
These levels take place in the dark, with Crash using a firefly to see. This element was later reused in Crash Bandicoot 3: Warped in the level Bug Lite and in Crash Bandicoot: The Wrath of Cortex in the level Knight Time. These levels are based off of two previous level themes, jungle and ruins. They take place in a jungle setting, except at night, and use the same music from the jungle levels. Two of the enemies (rats and spike lizards) are taken from the ruin levels.
There are 5 boss levels. They all take place in different regions.
- Ripper Roo (Boss 1, fought at a waterfall, with platforms surrounded by rivers).
- The Ripper Roo boss may be fought in a region similar to the stream-themed levels, or maybe even the same area.
- Komodo Brothers (Boss 2, fought in a circus tent).
- Tiny Tiger (Boss 3, fought in a futuristic space station which presumably is Cortex's space station due to the art style and lab assistants, but confusingly features a room decorated by Tiny who works for N. Brio).
- Doctor N. Gin (Boss 4, fought in a space port).
- Doctor Neo Cortex (Boss 5, fought in an asteroid tube in space).
Beyond the new moves, Crash Bandicoot 2 also features slightly altered physics and animation mechanics compared to the original making controls feel more responsive. Notably, Crash immediately decelerates (running or in mid-jump) as soon as the directional buttons are released.
- Directional buttons or left analog stick: Move
- : Jump
- or R1: Crouch / Crawl*
- : Spin*
- : View status bar
- Directional buttons or left analog stick + : Slide*
- + or R1: Body Slam*
- or R1 + : High Jump*
- Directional buttons + or R1 + : Long Jump*
- Directional buttons + + Releasing Direction buttons + : Glitched "Neutral Slide-Spin" where Crash covers twice the distance of a normal slide at the same speed. Useful for speedrunning.
- or R1 + simultaneously with : Glitched High Jump.
- Directional buttons + or R1 + simultaneously with : Glitched Long-Jump.
- Quickly alternating (wiggling) between pressing both perpendicular (to the direction of a jump) direction buttons while jumping will increase Crash's jump speed and distance covered
- Directional buttons + + while pressing + Wiggling + : Massive glitched spinning high jump bodyslam. Bypasses almost all terrain holes.
- Directional buttons or left analog stick: Move
- : Speed Boost*
- Directional buttons or left analog stick: Move*
- : Jump
- : Speed Boost
- + : Long Jump
- *In levels with Polar, the player can only move right or left, as Polar will move forward with Crash automatically.
Hanging from Meshes
- Directional buttons or left analog stick: Move
- : Let go of meshes
- : Spin*
- or R1: Legs Up*
- *These powers make Crash completely still.
- Directional buttons or left analog stick: Move*
- If the player presses the top directional button, it makes Crash move down, and if the player presses the bottom directional button, it makes Crash move up. So the controls are practically inverted. In the NTSC-US version, there is an option in the pause menu of both jet pack levels and the Cortex boss fight, to switch to "direct" movement where up goes up and down goes down.
- or L1: Move forward
- or R1: Move backward
- : Spin
- : Dive under (only when Crash is on burgundy colored ground)
- while underground: Spin objects
- Directional buttons or left analog stick: Move
- : Jump out
- Directional buttons or left analog stick (If the player is on a select screen): Select
- (If the player is on a select screen): Confirm
- : Show the Status Bar.
- Start: Resume / Pause Game
- In Warp Room 2, if Crash jumps on Polar enough times, he will get 10 lives.
Puns and references
- "Snow Go": pun on "no go".
- "Hang Eight": pun on "hang 10".
- "Snow Biz": pun on "show biz".
- "Bear It", "Bear Down" and "Un-Bearable": pun on the noun "bear" and the verb "to bear".
- "The Eel Deal": pun on "the real deal".
- "Sewer or Later": pun on "sooner or later".
- "Cold Hard Crash": pun on "cold hard cash."
- "Bee-Having": pun on "behaving".
- "Piston It Away": pun on "pissing it away."
- "Rock It": possible pun with "rocket" (homophones).
- "Pack Attack": pun on "Hack attack".
- "Pack Attack" could also be a reference to the game 'Pac Attack', a Pac-Man video game.
Crash Bandicoot 2: Cortex Strikes Back received generally positive reviews from critics and was considered to be superior to its predecessor. Much of the praise went to the game's graphics, control and music, with major criticisms varying between the trial-and-error gameplay, lack of level variety, easy boss levels and lack of innovation. The game went on to become one of the best-selling PlayStation video games of all time and replaced its predecessor as the highest-selling Western title in Japan, selling more than 800,000 units in the country by April 1998.
John Broady of GameSpot considered the game to be superior to its predecessor, commenting positively on the Warp Room concept, improved game-saving system and variety of the levels. The staff of IGN praised the "spot on" control and noted the decreased linearity of the game and increased intuition of the bonus levels compared to the first game. Mark Cooke of Game Revolution described the game as "undeniably fun".
The game's graphics were positively received. GameSpot's Broady described them as "in a league of their own among PlayStation games", while the IGN staff praised the high-resolution graphics as "beautiful". Game Revolution's Mark Cooke, meanwhile, went into more detail and started off by describing the graphics as "awesome". He noted the absence of cutscenes brought about by the entirety of the game being "rendered on the fly beautifully" and that the game could "really set some new standards in Playstation graphic quality." He went on to describe the animation as "flawless" and of "cartoon quality" and added that the game's "creatures, environments, and story building scenes are absolutely perfect." The game's audio was also well-received; Broady simply stated that the music "couldn't be better", while Cooke said that Clancy Brown's "hilarious satirical" performance as Doctor Neo Cortex added to the game's cartoonish quality.
Minor criticisms varied among critics. Broady noted that the semi-3D setup is "sometimes hard to navigate" and elaborated that "you'll find yourself missing jumps because you're unable to judge distances properly." Additionally, he criticized the trial-and-error aspect of the gameplay as "just plain cheap" and stated that "in some areas you must sacrifice many lives until you memorize a level's layout." The IGN staff said that the level design "isn't as varied as it could be" and added that the "jungle, snow and water" environments are recycled from the previous game and reused multiple times in Cortex Strikes Back. They also described the boss levels as "insultingly easy". Cooke observed that, like its predecessor, the game did not add anything to the genre and summarized that "the first Crash was dauntingly similar to the 16-bit platform games of yester-yore, only with better graphics, and Crash 2 doesn't deviate much from this formula." He also described the "bizarre 3D" cover art of the game as "unnecessary and evil" and "a device of unprecedented agony" and claimed to have contracted a massive headache after "looking at it in [his] car for about 15 seconds."
The game's success resulted in its re-release for the Sony Greatest Hits line-up on August 30, 1998 and for the Platinum Range on 1999. Crash Bandicoot 2: Cortex Strikes Back was initially released on the European PlayStation Network on July 26, 2007 but was withdrawn on August 7, 2007, along with Spyro 2: Ripto's Rage! , as a precautionary measure when the latter two games experienced technical problems. The game was released on the North American PlayStation Network on January 10, 2008 and re-released on the European PlayStation Network on February 2, 2011. At Sony's E3 2016 press conference it was announced that this game, Crash Bandicoot and Crash Bandicoot 3: Warped will be remastered on the Playstation 4 in 2017.
- The main theme is actually a remix of the one from the original game.
- The same goes for all the character themes for everyone who's appeared in the first game (Cortex, Brio and Ripper Roo).
- This game marked the first appearances of Coco, Polar, The Komodo Brothers, Tiny Tiger, and N. Gin.
- Also, this is the first game where Clancy Brown voices Neo Cortex.
- The player can choose to fight bosses again. On the platform in the middle of the Warp Room and press up while holding to refight the boss.
- In the NTSC version of this game, Tiny Tiger was misspelled as Taz Tiger in the pause screen. This was fixed in the PAL and Japanese versions, with him simply named Tiny. This is considered to be a provisory name that wasn't removed.
- In N. Gin's boss level, there are 20 missile paths in the data of the game, even though only 10 were used. A lot of these unused paths are also misplaced and can't hurt the player.
- The Secret Warp Room is made of the ruins of Cortex Castle. The castle was destroyed in Crash Bandicoot, as it is seen as being on fire during the last boss fight. N. Brio uses it as the base for his laser beam.
- The secret Warp Room also contains the 3D models* of the first two islands in Crash Bandicoot, although they cannot be seen clearly if a portal has already appeared in front of it (The third island cannot be seen since presumably, Crash is already on it).
- Each Warp Room is based off on different level designs. Warp Room 1 is based on Turtle Woods (level 1), and all of the jungle-themed levels. Warp Room 2 is based on Snow Biz (level 6) and all the snow-themed levels. Warp Room 3 is based on Sewer or Later (level 12) and the sewer-themed levels. Warp Room 4 is based on Diggin' It (level 17) and Bee-Having (level 20). Warp Room 5 based on all its levels except for Night Fight (level 23). The Secret Warp Room is based on Road to Ruin (level 14) and the other ruin-themed level, Ruination, (level 19).
- According to Jason Rubin, in the Japanese version of the game, a death animation of Crash being crushed and left with his head and feet was replaced. This was because the animation reminded Sony of a serial killer on the loose in Japan who decapitated his victims and left their head with their shoes.
- The game introduced Nitro Crates to the series.
- During the Nitrus Brio Holograms, a remix of the Nitrus Brio boss fight theme from Crash Bandicoot can be heard.
- A slight goof, regarding Crash's burning animation, involves Crash briefly turning into his Crash Bandicoot model before being reduced to cinders. This odd glitch also happens in Crash Bandicoot 3: Warped.
- If the player leaves Crash idle long enough, he will do his standing animation from the first game.
- The player can annoy Cortex and eventually make him very mad. To do this, one must start a new game, go into a level, and avoid getting the crystal. Once the player returns to the warp room, Cortex will get mad. If the player repeats the process, Cortex will yell. If the player repeats the process once more, Cortex will explain how to get crystals and how to advance. Cortex will also show what a crystal looks like. When Cortex explains he will have a tone in his voice that sounds very annoyed. This process will work up to 3 times.
- Many levels are snowy. It possible that the game takes place in the winter.
- In the intro for Crash Bandicoot 3: Warped, you can see Crash's strangely bigger, old surfboard hanging on the wall. His surfboard probably is so big that it is the size of Crash himself, most likely hindering him from riding it.
- Both levels in the sixth Warp Room begin with the word "Totally".
- This game is where Crash's pink boxers are first seen (when him and Polar run into an explosive Crate, or when Crash gets electrocuted). They are also visible in Crash 3.
- Hidden within the bookshelves in the Ripper Roo boss fight, thick game guides for the first Crash Bandicoot game can be found.
- The Japanese version of the game features Aku Aku giving out hints to the player. This makes this game his first speaking appearance, and not actually Crash Bandicoot 3: Warped.
- Coincidentally, there is an actual street in Erath, Louisiana called N. Gin Street. The N stands for North in this case.
- As found by Hacc, Monty Hall was the original name for the Warp Rooms. If one takes a look at the game's coding, each Warp Room is listed as "obj_monty_hall".
- In this game, Crash can dig underground to avoid certain obstacles. This feature was exclusive to this game until the release Crash Mind Over Mutant.
- The game has 1,889 crates in total (including the 10 crates from the Intro level).
- Instead of choosing the "Warp Room" option on the pause screen, the player can alternately exit a level by pressing Start, to pause the game, and then Select on the pause screen. These controls are left over from Crash Bandicoot and also works in Crash Bandicoot 3: Warped.
- By looking inside the warp room level files, it is possible to see an extra gem slot in Bear Down's sign. It's not programmed correctly, as no gem corresponds to it and if a gem is made to correspond by hacking, the lighting will not be correct.
- This is the first game to implement the Dynamic Difficulty Adjustment which awards Crash an Aku Aku mask or changes a ? crate into a checkpoint crate when he dies repeatedly on a certain section of a level.
- The image in the original European disc of the game has Crash tied on a rocket, exactly like in the launch ad for the first Crash Bandicoot game.
- In the cover of the game (see above), Crash isn't wearing his gloves. Naughty Dog wanted to say that "the gloves are off" with the sequel.
- The Japanese version has a method of calculating percentage different from the English version.
- The English version has 2% for each crystal, 1% for each gem, 1% for each secret warp found and 3% for defeating Dr. Cortex.
- The Japanese version has 1% for each crystal, 1% for each clear gem, 2% for each colored gem, 1% for each secret warp found, 4% for defeating each boss except Dr. Cortex, 6% for defeating Dr. Cortex, and 1% for getting the 10 lives from Polar.