Linux user here, running through ProtonGE10-1 on Arch Hyprland with Nvidia drivers.
Added the .exe as a non-steam game, and forced compatibility. Worked like a charm.
At the start, game looks awesome and runs quite smooth at 160fps at 1440p all settings max on my 3080. No issues with controller detection and fullscreen. Only had some wonkyness when messing with settings. It would show my cursor and resize but never quit out or bug out.
When I started to move tho, I noticed a slight bit of lag whenever I would go a direction. Sometimes I would run and it would still be at walking speed. I also noticed some graphical stuff like '!' bubbles trailing behind alerted trainers that were moving and IDK how I feel about the depth of field focusing, but it is a lil jarring. Running was also delayed, not as tight as on the gba. Also numerous times where a wild pokemon battle would happen as I'm leaving a grassy patch. Might be all in line with high-FPS issue, will test more.
However, I did hit the issue with the Team Magma Grunt battle 2 where it focuses on me but I never throw a ball, requiring a soft reboot. I was able to fix this by rebooting, saving after the 1st fight, soft rebooting to my save point, and starting the fight where I did throw a ball. This is game-breaking and should be Fix #1!
As for the battling and animations themselves, chef's kiss! No issues with audio as of yet, and I love the menus. Can't gush enough about this. Only real complaint is that I think the character sprite's face looks weird from the side like his whole nose took over him and from the back he looks like a bean man waddling to freedom. However, if this is by choice, Imma let the expert cook.
This is truly special, and I can't wait for the full release! Thank you so much UndreamedPanic, you are making our dreams come true <3
also on arch w/ Hyprland on an nvidia card, using proton-9.0 from the default steam compatibility list
most of the bugs are just because of the game being buggy and incomplete, however I did not encounter the same fps issues you have. One issue I did encounter, is hyprland crashing due to lack of vram (i have an 8gb 2060 super), but after restarting I never encountered the issue again.. not sure what happened there lol
For softlocks, on controllers you can hold (menu + A) / (options + X) or (menu + B) / (options + O) or something like that, I only recently found that out tho (i haven't played the game on keyboard yet)
game is amazing tho, wish to see a full release (hopefully with less bugs tho)!