Dirt Bike 3D 1.5

Dirt Bike 3D is a motorcycle simulation and action game. Using complex physics, it accurately simulates a dirt bike being ridden over various types of terrain. You design the bike, and you control the throttle and shifting to race against other networked players or computer-controlled bikes. Registered users can create tracks of any shape, including huge jumps, hill climbs, motocross, trials courses, drag races, and half-pipes.

I like the idea of this game but design and game environment is old.You can customize all settings in top menu of the game.Simply move the mouse (don't click) to give direction and press X key multiple times to take more speed.Take care at obstacles because are difficult to pass if you don't slow down.