1) Its free. 100% as far as I can tell. 2) Its a racing game, and a very pretty one with impressive gameplay, designed around playing online versus other people from all over the globe. 3) It will require analog input. That means a joystick, or steering wheel, or something. Mouse and keyboard will not cut it I'm afraid. 4) Its awfully fun, and its free.
I'm quite sure (due to the lack fo response) that almost noone has tried this game yet, but whether you've played it or not doesn't make this video of the game any less impressive. Someone patched together 1000 instant replays to make for quite an impressive video. Worth a peek.