I've been playing for years, and I have spent hundreds (if not thousands) of dollars on this, so please trust what I say:

Do not touch this game.

I'm not the kind that plays "free" games on any platform. I figured that I wasn't stupid enough to get into a "freemium" game, and certainly not enough to spend money. I don't play Clash of Clans, gatcha games, or any other mobile trash. I don't have mental issues, and I do not have an addictive personality. I'm just a normal person who liked D&D, and in 2017, I figured I'd give this a shot. How naive I was.

Just like any other modern phone game, this isn't intended to be a good game, and it isn't fun.
The goal is to addict you because that is how it's engineered from the start. And that's the entire point - it is a business model, not a game. That means it's packed with extremely predatory monetisation practices that nickel and dime you at every opportunity.

Poor design-wise, it takes a ton of time to manually optimise your teams every time you interact with it (got a new champion? Time to rearrange EVERY team you have!), pins your CPU a great deal wasting loads of power, and multiple times a week I encountered glitches that caused severe progress loss.

Yes, those are all bad, but not as bad as the monetisation that was slowly added over time that really turned the game into a glorified store with progression attached.

They sell "DLC" which are continually expiring in the store forcing false scarcity, sell back-to-back battle passes, hawk cosmetic skins for some reason that nobody can or will ever see, have constant mini-events with their own expiring currencies that they want you to purchase, repeatedly shove purchases and upsells via chests at you - even directly after purchasing chests, and contains hard progress walls that you CAN NOT progress through without scads of grinding or paying through the nose. Like an idiot, I did both.

Oh. And they raised prices recently and shink-flated the number and quality of items you got. Just FYI.

I had to stop, re-evaluate things, and realise that I wasn't having fun and was just continuing out of habit all while flushing money down a toilet. I was addicted to this garbage and am ashamed.

This game is gross.
The company making it is gross.
These game practices are gross.

EDIT FOR COMMENTS: There's a deeply weird number of people saying I spent a ton of time to fake my hours & achievements for this free game simply so I could give it a bad review (?).

Release Date: My earliest DLC is the Celeste Starter Pack from December of 2017. The game was not released in 2020, despite what the release date says on Steam - it was in Early Access for quite a while. Look it up.

Hours: If you're wondering about the hours I sunk into this, you used to not make any progress unless the game was left on in the background (which I often did 24 / 7), hence the hour count.

Did I play?: Yes. I've never cheated play time or achievements. I also didn't buy a bunch of DLC so I could post a bad review. That would be insane.
Here's a picture of my DLC ownership screen: https://imgur.com/a/TgTHSD9

Any further salty lying / complaining because you want to waste time standing up for a predatory mobile game will be deleted.

PLEASE NOTE, even though I have left comments on, I am not interested in you telling me that I should put 4000 hours into a game I don't enjoy so I can "git gud", and then I would like it. That is a stupid argument. Don't be stupid. Skill is not indicative of enjoyment, and I have better things to do than bash my head on what I personally feel are bad / mediocre games on the off chance I could maybe like them one day. I have a life and don't play games in order to develop Stockholm syndrome.

I played in 4k. I am using a 3080 & 5800X processor with all current drivers and patches manually installed on Windows 10 x64. I also played on Steam Deck.
I played with an XBox One X Pro controller and would not recommend a keyboard and mouse.

I will update this review if I continue to play and have more to add and will leave comments on.

PROS:
- The music and sound design were completely appropriate and fit the world.
- The cars are true-to-life looking and there's definitely a novelty to driving around a Hot Wheels course in a room.

CONS:
- Some pretty odd framerate dips for seemingly no reason. I am an I.T. director and keep my system in immaculate shape; this should not happen.
- Stupid "Live Service Game" season pass garbage. As such, the rewards for goal completion drop off dramatically after a few races. This feels like it was designed to be free to play, but changed their minds just before release. That or they'll make it Free To Play later on after they got enough suckers to pay for the main game.
- Extremely same-y racing. I've had the game installed for months, but just dreaded going back and playing it. There's no life or soul to any of the tracks, it's just the same crap layered on a new background room that you won't be looking at, because...
- The tracks are signposted extremely poorly. You should not lose the track in a racing game. That's unforgivably bad, ESPECIALLY when damn near everything BUT the path you're trying to find is lit up with neon orange and blue. I had games on the monster truck courses where I had to reset to track three times because every path I could see was wrong. I still don't know where I was intended to go. Messy course design is anathema to a well-done racing game.
- The monetisation is extreme. There's loads of things to buy (with real money of course), and there are exceptionally stingy "Season Passes" to give you a little bit more stuff, but no real reason to do so, because...
- I got one car in my second race. I then upgraded it immediately. It was better than any other car I found for the entire rest of the game. Why would I bother collecting cars if they all suck compared to the one I have? If there's nothing new to see, no new things to get, no fun, and no story, than what do you have to push players forward?
- The racing itself was mediocre. This is an arcade-style racing game, but for some reason crashing brings you to a dead stop, and most of the time it will not be your fault. Due to poor track layouts or unavoidable "traps", you'll just stop. Nothing says hot racing action like coming to a complete stop continually!
- Also, those spider traps can ♥♥♥♥ right off.
- The car sorting mechanism for new vehicles is worthless. It's just a huge line of them with zero sorting system whatsoever.

CONCLUSION:
This feels like a product designed to sell other products. It feels like someone screamed "CORPORATE SYNERGY" and this just appeared like summoning the world's ♥♥♥♥♥♥♥♥♥ genie. It was entertaining for the first hour, but the rest felt like a chore.

I always say that the true test of a game is if you are happy beating it.
I was not. The more I played it, the less I wanted to continue. That's a loss in my book.