Even though there is a Linux OS native build for Indemon Tales, I still reccommend to use Proton when playing it on a Steam Deck. Otherwise the mouse cursor might be buggy when switching to gamepad controls later on.


To do so, hit the gear icon on the right side of the game inside the Steam library and go to properties. There, you click the tab "Compatibility" and enable the checkbox for forcing Proton.


The game should now install and start normally

Once you are in-game, open up the menu and go to options. Tap on the "Controls" button once so you get to "Xbox Gamepad". Now close everything and you're done!