...Well if it had spikes, then it wasn't bottomless, was it?Yes it is. Mystic Caves spike pit, off the top of my head. And it wasn't appropriate at all either, just cheap BS.
Smartass response aside, play Sonic 2 and then Sonic Advance 1 or 2 immediately after. You'll see the difference. (Adv2 has a bottomless pit in every zone, I think. Let's check that.)