Crash Nitro Kart
  
Game Boy Advance
  


Play as Spyro:


Beat the game with all Team Bandicoot characters. 
Play as N. Tropy:


Beat the game with all Team Cortex characters. 
Play as Velo:


Beat the game.
Velo track:


Beat Velo in Adventure mode.
Play as Geary:


  Beat Geary at the Teknee track.

Play as Krunk:


Beat Krunk at the Terra track.

Play as Nash:


Beat Nash at the Barin track.

Play as Norm and Big Norm:


Beat them both at the Fenomena track.
Crash Party USA mini-game:


Repeatedly press L + R before the title screen appears. 





Artillery cheat:


Beat the Blue Gem Cup in Adventure mode.





Lunar cheat:


Beat the Purple Gem Cup in Adventure mode.





R/C Kart cheat:


Beat the Green Gem Cup in Adventure mode.





Turbo cheat:


Beat the Red Gem Cup in Adventure mode.




Thanks to Revolution readers rufus 33 and Cheesy Poof!