SImple answer: Yes
Longer answer:
The game runs smoothly on the 'Deck because there's a Linux build specifically for it.
Text can be small but I think it's still all legible. If not, there's always the magnifier (Steam button -> L1)
You'll need to enable the keyboard when creating a new boxer (Steam button -> X).
I love playing the game on the Steam Deck and I really hope you will too!
INSTRUCTIONS FOR STEAM DECK AND STEAM MACHINE USERS
To run the game on SteamOS you'll need to set the Compatibility Mode to Steam Linux Runtime 1.0 (Scout). In fact, any Linux Runtime will probably do but this is the only option I get and it works for me.
On your device, go to the game and then click the cog for Settings.
Choose Compatibilty.
Tick "Force the use of a specific Steam Play compatibility tool".
Choose "Steam Linux Runtime 1.0 (scout)" from the dropdown.
Install the game.
Do not try to install and run the game until you've done this: you'll be made to download a Web2View file, which is a Windows file and won't work on your device. If you have installed the game before setting the Compatibility Mode, uninstall it before going through the steps above.