I've been hearing about this indie game for a while, but I finally decided to try it. Extremely clever game in that the level structure and goal are the same each time (get the elephant to the pipe), but how you do it changes slightly each time. There are 30 stages to the level, and it took me about 20 minutes to get through all of them.
This is indie gaming at its best. If you haven't tried it yet, give it a shot: This is the Only Level