I haven't played this game in 14 years. You're not gonna get a mock screenshot. : )
I just remember that there was a big eyeball, and the ceiling around it dripped green stuff. If it hit you it hurt you, but if it was allowed to build up it formed vertical pillars. You could shoot out segments of the pillars, but the parts above would remain, defying gravity. I think the ceiling also moved up and down.
It wasn't "BattleToads," and I'm pretty sure it wasn't "Contra" either.