I'm not sure if it's helpful now, but here's what I think:
Pro: Very addictive, lots of depth within the story mode and creating your own racers, challenging, very, very fast and maintains a very smooth framerate, pretty tight control and decent sound.
Cons: Incredibly difficult sometimes (this game is developed by the same people who did the Super Monkey Ball series, and if you've ever played those games, then you should know what to expect here in terms of difficulty and frustration). The speed takes some getting used to, as you won't be able to make every turn on some of the courses the first couple of tries. Death Race not included, which was a mode introduced in F-Zero X. A-hole AI.
I wrote a review of the game on my website, and if you want to read it, click here:
http://www.angelfire.com/zine2/92530i/fzerogx.html .
It's a good, solid and challenging game. It can be frustrating, but if you keep at the challenges, they can be completed. I think you'll be pretty blown away and overwhelmed by the sense of speed. You really have to see and play the game in action to see how much of an insane experience it is.