For Soulstice players who are using Steam Deck, the game’s performance is very poor and I managed to achieve a fairly stable 30 FPS, let’s check it out.
Still in the game profile settings change the resolution to 1024×640.
Go to the “Compatibility” tab and set “Force the use of a specific Steam Play Compatibility tool” to the latest available version of GE-Proton. I tested the game on 7-35.
How to install ProtonGE?
Go to Desktop Mode and download the “ProtonUp-Qt” application in Discover. Run app and add latest version of ProtonGE to Steam. Go back to Gaming mode and in compatibility tab of Sunday Gold set “Force the use of a specific Steam Play compatibility tool” to GE-Proton.
Thanks to these actions stuttering will be minimized, and at very performance-taxing moments framerate will be more stable.
In SteamOS, set 60Hz with 30FPS limt. Also, enable FSR with 2-3 sharpness (personal choice).
In-Game graphics settings
SCREEN MODE: Windowed Fullscreen (thanks to this, the AMD FSR enabled in the SteamOS settings will work)
FPS LOCK: Unlimited
ANTI-ALIASING: High (we use a scaled resolution, so I do not recommend setting lower than high)
POST PROCESSING: Low
VISUAL EFFECTS: Low
With the above treatments, Soulstice should perform much better on Steam Deck. During cutscenes, there are occasional drops below 30 FPS, but the gameplay itself is very stable.
Of course, the game still consumes a lot of resources, so battery life is about 1.5h (25W).