All Working Crash Bandicoot: The Huge Adventure Cheats - GBA

Turbo
Successfully complete the game to unlock the ability to run faster in subsequent games. Hold [L] during game play to move faster.

Double Jump
Defeat N. Gin on the Boss stage on the second floor to get the Double Jump.

Tornado Spin
Defeat Tiny on the Boss stage on the third floor to get the Tornado Spin.

Defeating N. Gin
N. Gin's weapons are his weakness. There are four in all. At first, he starts out with a cannon and two missile launchers. After you defeat two of those, he opens a hatch and releases bombs. Knock out the cannon first and then put about the same number of hits on both of the missile launchers. This way, after you blow one up the other will not be too difficult to finish off. After that, blow up the hatch to defeat N. Gin.

Defeating Neo Cortex
Cortex is equipped with his shrinking ray. When you first enter his Boss stage, he will move across the screen, shooting at nothing in particular. After he does this twice, he will aim at you. At the same time, three platforms, each in front of three gems, will shift to a position that allows you to jump on top of one of them. Do this and wait. After a few seconds, Cortex's aiming target will start blinking red and yellow and make a noise like a teapot. This will let you know that he is getting ready to shoot. Just as he is about to fire, move or jump out of the way. If done correctly, he will blast the gem that you were in front of, and lose one hit point. You have to do this three times to defeat him.

Defeating eels
To kill the eels, press [B] on their heads.