This port breaks one of the late game bosses; a laser moving side to side attached to a ceiling. You have to stand on the side of the room with the most space to avoid it. Even if you stand on the far side the laser often comes to hit you (it should stop firing but doesn't), making it impossible to avoid. Been a while since I played the original, but there's also some weird physics bugs like falling through some yellow spring pads attached to a wall that I don't recall happening originally.