I know its nothing compared to some of the engines in here, but me and -liam- spent a while on this =P
Its a 'track and field' style controls racing engine... Just tap space as fast as you can to increase speed, your opponents speed is random and different each time, it traces your position when viewed in flash...
Race
This was my first copy of the engine, using kirby. The run animation plays when the speed reaches above 5, the speed decreases quite fast making it a bit harder, just tap space as fast as you can ^_^
Kirby Running