I tried running this originally on Proton 9.0-2 and it still boots, and is playable, (also loading into the game takes ages) but I noticed all FMVs will error out and will not play. Also the same will happen on Proton experimental. It works perfectly and the fastest on ProtonGE. The only things is there's a pulsing effect with the lighting, but I can't tell if it's Linux or the game its self as it has a cel-shaded look.

There is no windowed mode option in game. So this can't be tested.