A good game but without enough challenge and finesse.
Gameplay:
The Physics arent exactly top notch and landing a jump higher then 20 feet can be hard and usually ends up with the player flying over the handle bars, corners can be deadly too turning too much or not enough can result in flying off the track. You will get some fun out of multiplayer for instance having one player as an MX and another as a helicopter and seeing if you can jump over the blades of the heli but the time limit and lack of free roam mode in multiplayer restricts the fun.
Soundtrack:The music is quite good its got a few nice techno tracks mixed with some hip hop but the majority of music is rock which you would expect from a racing game.
Modes:This game has quite alot of modes such as Free Ride, Freestyle, Hill Climb, Race, Nationals and so on and so can be quite fun and varied.
AI:The AI is frankly quite terrible it does okay in some places but even on maximum difficulty they're not much of a challenge to even a mid ranked player with a 500cc bike.
Overall:While not being a casual game its absolutely not a hardcore racing game.
Verdict:Buy it, its only $10-15$ bucks so its not much of a drain on your finances and it might be fun.