Mole Mania has a couple of differences when played on SGB, apart from the typical border and color palettes.
RAM address C0A0 determines if the game is run on SGB or not. The leftmost bit is 1 if played on a SGB, and 0 otherwise. The other bits are uninitialized and don't matter.
On the file select screen, when playing on a regular Game Boy, there is a multiplayer option via the link cable. When playing on a Super Game Boy, this option is missing, since it lacks a Link Cable port. This option is also missing when playing on a Super Game Boy 2, since Mole Mania does not distinguish between a Super Game Boy or Super Game Boy 2, making multiplayer impossible on a Super Game Boy 2.
There is ASM code at 8:4128 that checks if the game is being run on a Super Game Boy, and displays the link option if not run on a Super Game Boy. This is only graphical and the code that actually lets the user select the multiplayer mode is located elsewhere.
TODO: Find the code that allows choosing of the multiplayer mode, based on whether the game is run on a SGB or not.
Music tempo and pitch
A Super Game Boy normally runs games too quickly, so Mole Mania compensates for that. If it is being run on a Super Game Boy, the music pitch and tempo are lowered -- the result is that the music sounds the same on a Super Game Boy as it does on a regular Game Boy. Again, this does not take Super Game Boy 2 into account, so the music is actually slow and flat on a Super Game Boy 2. The same thing happens on an emulator that ignores the extra speed of a Super Game Boy.
- ASM code is located at B:4030 (on the title screen, file select screen, cutscenes, and the level select screen) or 7:4030 (in a level) to lower the music tempo if run on a Super Game Boy.
- ASM code is located at B:459F (on the title screen, file select screen, cutscenes, and the level select screen) or 7:459F (in a level) to lower the music pitch if run on a Super Game Boy.