Just beat the "main" portion of the story mode for TSR, though I haven't done all the challenges. I can't help but feel they dropped the ball on several aspects. Having to rely on AI teammates to beat many challenges is just frustrating, because the AI teammates suck. Team ultimates feel pointless unless you use them near the end of the race, and there's a lot of annoyances with using them. Despite the fact that team ultimates are supposed to give you a speed boost and make you charge through obstacles and rough terrain, weird things like failing stunts will halt you while the ultimate is still going. Not to mention, the speed increase of using one can cause small bumps/ramps to cause you to fly way off course. Finally, team ultimates end before the theme does, meaning you can't rely on the theme to let you know when it ends. Many wisps feel incredibly underpowered, except the lightning, which is worse than any blue shell, because it completely stops you for a good several seconds, and it's near-unavoidable. Speaking of being stopped, if you get hit by anything that really slows you down, there is no way to quickly recover, besides boosts made utilizing team mechanics. Get hit right before a boost arrow? The arrow will not speed you up right afterward, even though you see it activate. And it really feels like the AI cheat on harder difficulties. Having max speed stat seems to mean nothing. Except in the final world, which, for some reason, is the easiest of all the worlds, because you're racing against almost entirely egg pawns, which suck an incredible amount. I won't spoil the finale, but it's incredibly underwhelming and disappointing. To make matters worse, you have to beat the story mode if you want the three Eggman tracks.
I don't understand how they could mess so many things up, after how good All Stars Transformed was. A lot of aspects feel like a downgrade, and most of it can be blamed on them trying to push the shitty team gimmick. It's such a shame, because everything else is so good. The soundtrack is amazing. The tracks are really cool, though certain themes get repeated a bit too much (three entire tracks are just slight variations on Planet Wisp). The cast is well rounded, even if there are some bizarre decisions. Kart customization is pretty cool, though they cheaply increased the number of parts with the "legendary" variants. TSR could have been great, but it really needed more work and to drop the team gimmick.