Go to the password screen via the main menu. Input these using the d-pad:

Minion: Right Right Right Left Left Sweet Tooth: Left Left Left Right Right

These are not cheat codes. These are for use while in-game. These are inputs you make on the d-pad that utilize your energy (the purple bar on your HUD). The three I use very frequently are:

Freeze Missile: left, right, up High Jump: up, up, left Rear Fire: left, right, down

You can also use this one, but, so far, it is useless for speedruns: Invisibility: up, down, left, right