Top Banana is a platformer game originally released in 1991 for the Acorn Archimedes. It would be later ported to Atari and Amiga in 1992. The game is most well known for looking really creepy. I honestly got Undertale vibes from this.
Credit for footage goes to @RetroGameManDan79
Boss List:
00:00 Head (Forest)
00:26 Robot (City)
00:46 Temple Guardian (Temple)
01:11 Final Boss - Color Face (Dream Land)
01:34 Ending