Enter the following passwords for the Chrome subgame:
At the title screen, quickly rotate the directional pad in a clockwise motion starting with the Up position. If you go around several times, you'll see a white flash in the background. After the first flash, press Up repeatedly until the flashing stops; you should see a total of four flashes.
The first flash activates a stage-skip option, which you can use at any time during the game: Just press Pause, then hit B to warp to the beginning of the next stage. The second flash gives you infinite energy, the third flash grants unlimited ammo and the fourth flash gives you unlimited credits in the weapon shops!