Don't run -- gallop! The maker of QWOP and GIRP has just released CLOP, a QWOP-like game featuring a four legged unicorn instead of a two legged Olympic athlete. I'm having a lot of fun with it; I rather like these games where you have to balance the physics of your vehicle (or in this case, equestrian.) They're just delightful in their simplicity.
Trials Evolution for instance is very fun, but I have to say, the element of controlling all four of the unicorn's legs adds a whole new degree of difficulty. My strategy is to cycle through the keys (H,J,K,L) from right to left at about the gait of a running horse, and that seems to work for awhile. I still have yet to get my unicorn over the first hill though. How far can you get?