Proun is a pretty unique racer which Track Mania fans will enjoy. It is a "pay your price" game which means that you can get the game for free or pay whatever amount you want to for a few extra tracks.The game requires players to use proper timing in order to make the right turn and twist so you need to have a lot of dexterity just to get a podium finish in the most basic difficulty. Unlike Track Mania though, the tracks are riddled with obstructions which are inspired by modern art, at times they even resemble a kaleidoscope; not to mention tracks structured similar to a roller coaster.
The difficulty varies the speed of the ball, the faster the ball, the tougher it gets to navigate through the obstructions. The game can get insane and perhaps impossible to play at higher difficulties but don't let that get you, one can achieve a podium finish with proper practice. It is a pity that there are just 4 tracks in the game (you get an extra track if you've paid for the game) out of which one doesn't get unlocked until you've beaten the game in super sonic mode. The game also supports spilt-screen upto 4 players (yes, on PC -WASD and arrow keys), two extra players require game pads. And yea, there's the time trail mode which allows you to compare your times along with players around the world.
To sum it up, if you're into whacky racers, you should check it out.
And a little warning - You might just get a little dizzy after long hours of play.