Zero the Kamikaze Squirrel (SNES)

Zero the Kamikaze Squirrel
Developer: Iguana Entertainment Publisher: Sunsoft Platform: SNES Released in US: November 1994 Released in EU: March 30, 1995 This game has a hidden level select.

Zero the Kamikaze Squirrel is a spin-off series from Aero the Acro-Bat, starring one of the enemies found in the latter. It's basically what you'd expect a ninja flying squirrel game to be.

Level Select

During gameplay, pause and press Right, Up, B, Y, A (RUBYA). Press Up and Down to select a stage, and hold Select and press Start to advance to the selected stage.

Alternatively, pause and press Right, Up, B, A, Down, Up, B, Down, Up, B (RUBADUBDUB) to bring up the level select, which additionally gives you unlimited lives, energy, and shurikens.

In the Genesis version, the first code is different and the level select takes place in a purple screen, featuring a bouncing "PLEASE SELECT:" text.