in the beginning it is hard but after a while you will see that it is simple to use.
for example to create a body you will need 3 steps but instead of doing it every time i created code modules and i do it now in 1 line.
so you can make life much simpler by adding functions...
box2d do all physics in the background and the most important stuff is the collisions detecting.
the game is really in his first stage and i will also change the graphics.
my next steps are: creating start menu, creating bike settings (motor, wheels, axis strength..), leader board, adding 6 different bikes, adding a driver that is connected with joints, adding more levels (night mode, snow, desert,..), adding coins on the road, adding fuel on the road, adding tachometer, sounds, different animations like rain/wind/fog,...
so in the end it will be a nice game i hope
i don't think that this will become a big hit but what this game will do 100% is increase my box2d knowledge.
it is not a simple project and it will need more time as usual for my apps but it is worth for me.