Humans and creatures option:
Have a character on your team get their weapon fully upgraded in single player mode. Alternately, have no characters on your team miss during an entire level in single player mode. This option is unlocked at the battle mode team types menu.

Defeat leader option:
Have all team members complete an episode with 100% health. This option is unlocked at the battle mode objectives menu.

Custom option:
Get a 100% hit head shot status two times in a row. This
option is unlocked at the battle mode team setup menu.

Level select option:
Successfully complete the game two times to unlock the
level select option.

Team power option:
Get two head shots in a row. This option is unlocked at the
battle mode menu.

Unlimited turns and movement:
Press Up(2), Down(2), Left, Right, Left(2), R,
L during game play.

Big heads:
Press Up, Left, Down, Left, Down, Up(2), Left
during game play.

Disco mode:
Press L, Left, L, Left, R, Right, R, Right during
game play.

Low gravity:
Press Up(6), Down, Right, Up during game play.