One of the Sega Genesis games I've become familiar with recently is Decap Attack, where you play as a headless... mummy... something... that has some unusual methods of attack, namely smashing things with the extending face in his chest and, when he has it, flinging his detachable skull (which is a powerup that is lost when he gets hit... and has nothing to do with his chest face).
Oddly enough, it's a lot more effective than the attacks a lot of platformer characters use (cough cough Mario), partly because his chest face attack can stop enemy projectiles, plus the skull sits where it lands for a little while and continues to hit things-and even hits on the way back.
Of course, the reason it's so odd is because it's actually a reskinned version of some other game where the skull is essentially some kind of semi-autonomous creature and the chest face attack is a boring regular punch.
The original game's graphics frankly look a lot less interesting; there's none of the general weirdness and the Decap Attack graphics seem to just generally be newer and higher-quality.
And then there's this boss, who appears to be a giant mole wearing sunglasses.
Giant mole? Pointy sunglasses? Could it be...?