For a lot of them, they need to be entered in a specific "secret code" slot...
Link, Heckknow says (and i tried it, it works):
Secret Code 1 - BOTOFWAR (kills or stuns everything within range)
Secret Code 2 - STEALTHARMOR (can move undetected/unoticed by any enemy)
Secret Code 3 - RAINBOWLASER (laser switches color continuously)
Secret Code 4 - EXPLOSIVEWORLD (every cubes are explosive cubes)
Secret Code 5 - GLOWINTHEDARK (lights dark areas)
Secret Code 6 - BOTOFMYSTERY (wears ski goggles)
Secret Code 7 - GOLDENTRACKS (golden tracks)