Compatibility Report

• Name of the game with compatibility issues: Gumboy Tournament
• Steam AppID of the game: 11230

System Information

• Steam Deck (LCD)
• Video driver version: 4.6 Mesa 24.3.4 (git-8d0948917e)
• Kernel version: 6.11.11
• Proton version: 1763652710 experimental-10.0-20251120

I confirm:

• [x] that I haven't found an existing compatibility report for this game.
• [x] that I have checked whether there are updates for my system available.

Symptoms

If to install and run it from Game Mode - it locks up with a black screen (with a Steam controls stripe at the bottom).

steam-11230.log

For some reason its UI windows aren't shown while in Game Mode - you need to switch to Desktop Mode, run it there, agree to install Mono, agree to not to show a window/fullscreen selection window on further runs - and only after these operations it can be run/played from Game Mode.

Reproduction

Install and run the game from Game Mode.