Medium Awareness: Don't be surprised to see snails reference the fact that they are in a game. Particularly notable in this quote:
"Don't moon snails live in the ocean? Hey, this game isn't realistic!! What gives??"
"I hope the next game has more weapons. This game could have used a flame whip!"
Minus World: ???, with its weird glitchy walls and strange music. It's actually the passageway to the Shrine of Isis.
Mirror Boss: Moon Snail. Aside from changing his own gravity, he uses Devastator-style boomerangs and dark-colored waves in his first form. As Giga-Snail, he uses bigger Rainbow Waves, as well as using the Devastator-peashooter bullets. He even uses the idle animation as an attack; the Z's fly off in your general direction.