Team Sonic Racing

In my opinion, this is the weakest of the 4 Sonic Racing games currently on steam. I can still recommend it, but barely. At its core, it's a very competent kart racing game. The driving is fun, the tracks are fine, the character is there, audio and music are pretty good, too.
Team Adventure was a good idea in theory, but it has bad execution and it explains why they didn't bother to have a story mode in Sonic Racing: Crossworlds. The story segments are all one note, not animated, and don't really add much to the game's presentation. The team racing aspect is easily abusable by constantly transferring and requesting item boxes to your teammates as much as possible and the special itself only seems to amount to you having a speed-up for an extended period of time. It also seems like most of the game's race tracks are just recycled from the previous 2 titles, so while they're fun to race on, we've seen most of them before.
It's also extremely annoying where it seems you get penalized HEAVILY when you get hit. Often you'll come to a complete stop, other times you won't be able to start moving for a period of time. The game DOES do some cool team mechanics like the slingshot and basically what is a more annoying version of the slipstream mechanic from crossworlds, but only with your teammates. Sometimes the sudden speed ups that you get from your teammates are so fast you careen into a wall.
This'll be fun to play at a significant discount if you've played the other 3 and just looking for something else. Otherwise skip this one. This "recommend" I'm giving has a heavy "*" next to it. It's not a bad game, but it's outshined by the other 3 sonic racing titles available.

A good and fun alternative to a certain cart game with a plumber.

Great game, it's sad that online is dead. There are still groups of people playing the game, if you can find them. solo campaign is still pretty fun against the bots which are decently challenging on Expert and getting 100% feels pretty good (EXCEPT for that one achievement that forces you to sift through leaderboard menu for forever manually). The team mechanics are actually pretty good.
I just really wish online wasn't so dead.

A mixed review from me personally, though more towards the positive side. While having less single-player content than its predecessor, Transformed, they did add a story mode with a variety of missions and objectives. Much of the technical depth from its predecessor is removed or simplified to be more accessible to the average player, which can be an up or downside depending on what you're looking for in these kinds of games. The driving is still satisfying to learn and execute, though the tracks are definitely a downgrade from Transformed. That's not to say they aren't interesting - most of them at least are worth learning and taking in the scenery for. Most of the reason I think this is mixed is because it's double the price of Transformed. I would grab this game on a half-off or better sale, though not at full price; it hasn't aged as well as the first two games in the series.

For most people, go play Sonic Racing Crossworlds or Sonic and Sega All Stars Racing Transformed instead of this.
But if you find it on a really deep sale, it's not like there isn't any value in it. It's just really hard to justify unless it's dirt cheap (like less than 10$)

Its ok, but nothing special. Play the new one, it's what you want.

Not as Bad as people made it out to be. It was clear Sega did not allow them to finish this properly, but what is there mostly works including the online.

Give it a shot.
It still runs well on most hardware.