Slippery Climb
From Bandipedia, the Crash Bandicoot wiki
Slippery Climb is the twentieth level of Crash Bandicoot. Some consider it to be the hardest level in the game, taking place on the side of a thunderstormed castle wall, presumably Cortex Castle, Crash climbs up the difficult wall facing birds with look like vultures, spikes, potion throwing lab assistants, trained by Doctor Nitrus Brio, moving platforms and stairs, and other obstacles. There is a Tawna bonus round and a Brio death route inside it as well. The Red Gem is obtained if all crates are broken without death in this level. Stormy Ascent, is a level just like this one but was cancelled before the game came out.
