Soldier Collection

Press Left two times, I, Right two times, II, Up, Down, Up, Down at title screen.

Press Left two times, I, Right two times, II, Up, Down, Up, Down while "Set-Up" is highlighted.

Hold Up, press Select. Hold Down, press Select. Hold Left, press Select. Hold Right, press Select. Continue pressing Select to view the new starting level locations (for example, Stage 2, Stage 3, etc.).

Destroy both hands of the stage 7 Boss and wait for the words "Bonus Stage" to appear. Collect it for something saucy.

Select "0A" at the "Sound Test" menu, then go to the difficulty option. There should be one more difficulty setting available.