At first I thought this was a crappy mario kart ripoff, but I found I was wrong.
This game takes the best aspects form mario kart and adds sonic characters and some breath-taking levels.
Seriously, these are some of the best levels Ive ever seen in a videogame, the vibes, effects, colors, everything just pops.
Make sure you play this at max settings.
My only complaint is the flying levels, flying is really awkward, not extremely difficult, but it changes the pace of the race in a bad way. Its also difficult to hit opponents, turn, and its easy to get stuck on various objects.
Other than that imagine mario kart 8 on steam with sonic rather than mario.
Also they add people from all of segas games, not just sonic. So its more like SSMB x MarioKart.
Pretty good, great for local gameplay as well.