I've been thinking about ice actually, the setup I think I'll head for is when your on walk on ice, you skate till you bang something (or die), but to overcome that (as a player), Dizzy styleeee, you have to have some spiked shoes.
This is how being in water will work, yeah, at the minute you can take a dip, but when I move on to items, your going to need to be carrying a snorkel, ala Dizzy2 or you'll drown.
Dabz