Its a fun way to pass the time, but by no means is it a true sim. I spent many of hours playing motorcross madness (never the second one though), and the physics and feel of this game is nothing like the original. Even on hard this game is way to easy, its very difficult to crash and im using just the keyboard. You can actually go threw an entire race without leaning and not wreck, its not fast that way, but it is possible. It is helping me kill some time here at work though so its worth the $9 to me, but at the very least some form of a series or more opponents then 6 would be oh so nice....
Oh and it does work just fine on windows 7 64 bit.