Collect all the barrels with your wheel, then find the exit to the next level. If you're good, you'll be able to capture some stars! The exit to the next level only will open after you collect all the barrels. Progress through the 5 levels of the game. The sixth one, more difficult, only will be enabed after you collect all the stars in all the previous levels.
Arrow keys left/right to move. Once you went through the open door, space bar to go to the next level.