Been playing Sonic Superstars and, yeah, like pretty much everyone else has said, it just feels like another bland Sonic game. I feel like I should be enjoying it more since, on the surface, it feels like there isn't anything particularly wrong with it, but it doesn't invoke any strong emotions in me either like Mania did. Plus the new Chaos Emerald power system is really awkward to implement.
Trip is a pretty cool new character, I guess, in terms of gameplay. I'm playing her run now, which is basically just playing the game again on hard mode. And yeah, this game is surprisingly tough for a Sonic game, but not really in a fun way. The game is forgiving enough in that you have checkpoints and infinite lives, but the boss battles are really long and aggravating.
I'll probably finish it up today since I've got about six more stages to go with Trip and I have all the chaos emeralds. Incidentally, the chaos emerald bonus stages are really awkward and poorly designed, but...strangely I didn't have much trouble with them. I don't think I had to do any re-attempts.