It works fine on Steam Deck
End of the statement.
What? Want more details? Okay then...
Playability
Single player modes
Basically, you can play the entire the game normally, because the videogame's controller layer is the same as the Steam Deck's.
Play quick matches against the AI
Enjoy the arcade mode
Local multiplayer
If you have a Steam Deck, you might have noticed that it's designed for one player, so you have two options:
Plug a second controller. You can plug it directly with an USB-C cable, or, if you are using a dock for TV display, you will have some USB ports available
Be extremely creative with the button layout. You can manage to play with two players on a single Steam Deck. Probably. Maybe*
*We won't take responsibility on the possible damage made to the device
Network Multiplayer
Here you have some options:
LAN multiplayer: It should work as in PC
Online multiplayer: You will have the same issue as in PC, you both will need to be connected to the same VPN. But I'm not sure how to do it on a Steam Deck
Steam Remote Play Together feature: So, if you don't want to bother with that, then you can use this feature, with the advantage of only needing 1 copy of the game to play!
So, yeah, the game is fully playable and enjoyable on Steam Deck.
Steam Deck compatibility assessment
*Note: At the time of writing this, Thumps & Blows doesn't have an official verification on its compatibility with the device.
Valve has a well-stablished criteria for the Steam Deck compatibility verification, so the expectation is that Thumps & Blows will have the "Playable" tag, instead of the "Verified" one, even when it is fully playable and compatible.
That's due to minor details:
Steam Deck controller icons aren't displayed, there are only generic icons
You have to call the device's virtual keyboard manually. You don't have to write a lot on this game, but it's required for certain actions, like adding a friend to connect with
Some text might be small and difficult to read in the device's screen
The game's resolution is 16/9, but Steam Deck's is 16/10
These issues aren't impactful enough for the game enjoyment, so don't worry, you will have fun anyway!
The thing is that solving the majority of them would require a lot of time and technical solutions out of my possibilities, so, for now it's not worth to me.
Performance and technical specifications
The game runs perfectly on the device, even using Proton instead of a native Linux build.
60 FPS
Short loading times
Very low battery consumption
Performance is even better than on regular PC
That's because Thumps & Blows is not a demanding game, and given that the engine, Ikemen Go, is so well optimized. Honestly, most of potato devices could handle it.
So, yeah, it works fine. Probably, some day a native Linux version will be considered, because Ikemen Go has a stable version for Linux, but it works so well with Proton that it's not necessary.
So, that's it. Have you tried Thumps & Blows on your Steam Deck? Let me know in the comments!