One of my favorite series is Mario Kart. I've played them all, and it was one of the reasons why I even got my new 3DS. So I had to take Mario Kart 7 out for a spin.
It's sadly not a drastically evolved game. Since I played the six previous games, I easily jumped right in. Had no problems out-racing the computer opponents.
The only real new feature is the ability to glide during big jumps. It's fun, but doesn't add much to the game-play.
But I'm glad they included the retro courses (like Mario Kart DS and Mario Kart Wii did) once again. I thought the new courses were pretty neat as well. I haven't raced online yet, but I'm enjoying my time so far. Hopefully it won't be ruined by bad players like Mario Kart DS did.