First time I've played this game (thankfully, it was many years ago), I had very tough moment in my life and I was feeling extremely unlucky. Of course this game didn't solve my issues (this came a bit later, thankfully), but how it gave me a lot of fun! Fun! Fun! I was genuinely cheered up, first time for a long time.
And for a good reason, because the game is so engaging as it could be, with vibrant, living tracks, huge variety of racers (this game presented unique vehicle for each racer, in opposite to later games in the "series", which have unified a lot the vehicles).
It's the game which you can start playing almost immediately, very intuitive, in terms of control, power-ups, learning tracks etc. With great gameplay comes also great presentation, and music tracks are incredibly catchy. I didn't know it back then, but there are plenty inspired by Sonic Heroes tracks (also music themes are "borrowed", and they're probably the best tracks in the game). There are not only Sonic characters, but also some heroes from other Sega games, so it's nice "nostalgia" trip as well.
I can't recommend this game enough, it gave me plenty of fun in very sad moment, and later... Well, it was still great, no matter how many years after I've launched it again. Highly recommend to play it, alone or (even better) with someone else in split-screen mode! Fun!