Tux moves slowly on ledges, and he can switch between hanging from them to shimmying across them at any time by pressing the down and up arrow keys.
Ledges would also be unisolid, jump up from below and Tux would hang from them.
Tux can also jump off of the ledges when hanging, and jump up to avoid/stomp a flying enemy when shimmying.
Walking enemies treat ledges like empty space, they either fall off or turn around.
I had another idea, a bit more random. How about a mountain goat powerup that lets Tux move on the ledges at normal speed?
Lol, probably not.
