Nitronic Rush is a game made by students at Digipen, its free and available for download here:
http://nitronic-rush.com/Even though its a student game its incredibly well made and has many features
It has dozens of achievements, a short story, many challenges, 2 stunt tracks, and alternate levels that are made to be much harder (called hardcore mode)
It even supports controllers, and recommends you play with one, which i too would recommend to play this game with a controller
The racing itself is alot of fun, you can drive up walls and on ceilings and even fly
The yellow is the road your supposed to be on but with flight you can reach other places
Hardcore mode is very hard, the main game is a cake walk compared to it
You have to transition between walls floor and ceiling using your boosters, flying is disabled in that mode
You have to jump and use your boosters to flip the car upside down in order to get on the road above you in hardcore mode
The faster your moving the easier it is to stick to surfaces, so you need to keep up a good ammount of speed to drive upside down or on walls
Riding on walls and upside down can get confusing, the only reason i know im on a wall here is because the score counter tells you
Directly in front of me is a ceiling transition, but since this was taken in the normal game mode it will automatically switch you to it
It has tutorial modes (2 of them, 1 for normal mode and 1 for hardcore) to teach you how to boost and fly
The hardcore tutorial is important because of how you have to transition between walls/upside down
The game is really well made and i have no complaints with it and since its free you should definitely check it out
It has online leader boards to compete with your score and time
If you go into the Options theres a button labeled Online Group, if you click that and type in TMMM you can compete against my scores directly your score will be added there so anyone that types TMMM in the online group will be able to compete on that score board
You also see a ghost of what other players did on the track while you race