First, this was only like 10-13 hours of content, not 20. This was just like 3 new dungeons, and another small part of the story. The Story was kind of meh, maybe one or two cool things, bosses are lack luster. Definitely not worth $30
Had a really good time with this game. It's not too long. Love Aya, had more similarities with her than I thought I would! There was only 1 area which wasn't that good, but the rest of the game felt fine with everything it did. The ending was great as well.
Multiplayer is difficult to do in 2D Sonic games but I still enjoyed it, had some good laughs. Single player zooms the camera in too much. Characters are fun, (except Knuckles got nerfed again) some powers are fun to use. Final Boss is fun and challenging.