For me the game would crash shortly after launching until I forced the use of Proton 7.0-4. Otherwise it runs flawlessly.

Celaria does not support controller input natively, so you must emulate a keyboard and mouse layout. For navigating the menus I like to use the right trackpad "as mouse", and bind right trigger to "left mouse click". For gameplay I've found that setting the bindings similar to Mirror's Edge works well (left bumper = jump, left trigger = crouch/slide). Right trackpad is also used for aiming/look. The X button by default is bound to "R" which will restart the current level.

Overall a good experience with minimal tinkering.