Tempo

Tempo is a cutesy 2D musical platformer for the ill-fated 32X that also had horrendous US cover art. It was followed by Tempo Jr. for the Game Gear, then by an awesome Japan-only Sega Saturn entry crafted by the masterminds behind the Bonk/PC Genjin games.

Debug Menu
The debug menu remains in the final, but was dummied-out. It can be accessed by modifying the address or by using Game Genie code  in the Gens emulator (it won't work on real hardware).

To toggle it on/off, hold A + B + C and press Right on the D-Pad. To change between CG mode (patterns) and CL mode (colors), hold Start and press any direction on the D-Pad.

To change the select mode, hold A and press a direction. When in "cell edit" mode, press B to overwrite a pixel with the current color (selected in CL mode).

Unreachable Endings
2aN3vHSEkq4 There are six endings, with different pictures shown during the credits, which are given depending on your score. Unfortunately, even when playing in Hard Mode (with 10x bonuses), skimming through the levels flawlessly and having a perfect performance at Bonus Levels, half the endings are still inaccessible due to some obscenely-high score requirements.

This said, it is possible (but extremely hard) to get them normally without any cheats by abusing continues and grinding in the last level for about six hours.

An early prototype had enemies giving more points when defeated, so it seems the programmers forgot to lower the score requirements as development progressed.