First off, this game is NOT worth full price. The complete and total lack of voice actors make it a $10 game at absolute most, but I'd recommend waiting for $5 or less. It's still fun, but it would be SO MUCH MORE fun if Raph yelled at the other racers or Zim cackled on the podium. The Challenge Mode provides a fun way to earn new racers and power-ups without just rewarding the player for doing something super repetitive; like after every couple of races or for getting first place online. I can't even really recommend it for kids because half of the recognition of a cartoon character is the voice. Really, my biggest gripe is that there are absolutely NO voice lines at all.