
- Make every car unique! Every car should have it's unique specifications (weight, speed, manoeuvrability), like cars in the game called "Re-Volt" (12 years old game similar to STK): http://www.youtube.com/watch?v=uUQM6Eir7PI
- New cars and tracks should be unlocked after the player successfully completes a challenge
- Add more weapons (check out the video link above for more inspiration)
- Add built-in track editor (not everyone is able to use Blender) and let users to create their own maps!