Game is dead and unsupported. I've received items in game which are supposed to be disabled from old events, they are unusable and unremovable, so now they just take up space on the map. I've had a 'support' issue opened with it for nearly a month with no change. Please upvote for future players' awareness that the dev is no longer supporting the game.
Bugs in landing on a down-ward travelling platform and collision detection with spike blocks. Makes it more frustrating than it should be, and really distracts from what seems like an otherwise decent game.
Level 6 needs work. Alignment detection for getting the ball to drop down a level, rendering progress entirely subject to control outside of the player's hands.
To get the Going the Distance achievement, ditch the groupies and run solo, try to land with the wheels flat, and cross your fingers. The groupies add score modifier, but they also add weight and slow you down.
Fix the wall climb! Fine, it's long and challenging. Put a brick in mid air somewhere so you can land on it and resume your climb from that point instead of falling all the way back to the beginning.