The problem is that the game has about 2 hours worth of content at best and is way too unbalanced to be enjoyable as a multiplayer game. The mix of collectathon and racing gameplay is unique and the music is fantastic.
R is genuinely a fun game once you get used to the controls IMO (think of the characters as cars that can jump instead of as platformer characters). Definitely not a game that I want to replay all the time though. The gameplay has a ton of flaws but it's short and easy enough that I'm able to overlook most of them. The game looks and sounds fantastic on both consoles it was released on. 3D Blast is a decent time if you like the classic Sonic aesthetic.