Enable cheats for 30 seconds:
up up down down left right left
L3 + right
restore time dilation:
L3 + up
Get More Plasm
To get more "Plasm" points from each kill, get in as many consecutive hits as possible. The more consecutive hits you get, the more damage you do and the more plasm you get from each kill... which essentially means more powerups faster!
Kill enemies faster
When fighting an enemy switch to sword mode and walk up to an enemy and press o. when they go up in the air wait till they come low enough for you to hit them the press o again this one more time and this time when the come down do a shining sword (press square) to finish them off fast.
How to beat the "Venus fly trap" boss
As soon as you enter the chamber were the boss is at, he will focus on you before shooting a laser beam. Quickly switch to stealth mode and turn invisible. while in invisibility mode get as far away from the laser beam as you can. After the he has shot the laser he send out an explosive bug, jump in it while in stealth mode then (while on the explosive bug) switch to gunner mode and fire the bug into the bosses mouth. repeat this process about 3 more times. although the bosses will send out more bugs. make sure to destroy all but one to shoot into he bosses mouth. When the boss freezes and open his mouth really wide quickly jump into it in human mode and slash it a couple times. wall-lah!