It would be helpful for solving puzzles if you could keep adding paths even when you go over the limit, and it just doesn't let you pass the level until you get the right number of blocks. Otherwise great game. 5/5. :)
You should get more money on later levels, the only way I can beat some of the final challenges is by replaying the first level to get money upgrades. Also, most of the really good bikers are unlocked near the start of the game (like the viking, who's good for racing), and a lot of the late ones aren't great (eg, Rocket Man, who took me about an hour to get, and only ever used on his challenge level), and it would be better for bikers to improve as the game goes on. Joke characters are awesome, but a progression is still good to have. Great game though, 5/5.