It was a game I played quite a long time ago, but I think it's since been closed down. The entire game was about competing with several opponents in races on foot while going along tracks with different themes.
One of those tracks was a pyramid level, and you had to solve an equation and go through the right door or you "died" and had to restart further back.
Another level was just you running from a shark who was chasing you while going through various different obstacles.
It also had a third person over-the-shoulder camera.
I'll add more info if I think of it, but I really would like to know the name of this game and what happened to it, since this was the game I played constantly several years ago.
EDIT: Game is Talesrunner, thanks Otto!
