Slitherine

I know that this game isn't young anymore, but I have been trying to play it on Steam Deck and it's very frustrating. I have checked Steam forums as well as ProtonDB, but in the latter case the last updates are 5-7 years old.

So, I tried playing on Steam Deck with modern versions of Proton, and there were always screen issues: menu text running together, improper resolution, no response from any controls etc. Finally, I rolled the game back to... 6.3 (I think) and it looked great: The intro video played well, the simple 'mouse-only' control scheme that I wanted to use was working, and the title screen was just right - I could even change the flags at the bottom of my screen to my preferred language. However, the game will not recognize any of the campaigns that I own under this version of Proton. I've tried rebooting the system and a few other basic things with no luck.

I want to keep this post succinct, so I will stop there. I'm sure that a fair few people have played this game on SD, and I would like to be able to also.

JustJeff88 wrote: ↑Sun Mar 15, 2026 9:25 pm I know that this game isn't young anymore, but I have been trying to play it on Steam Deck and it's very frustrating. I have checked Steam forums as well as ProtonDB, but in the latter case the last updates are 5-7 years old.

So, I tried playing on Steam Deck with modern versions of Proton, and there were always screen issues: menu text running together, improper resolution, no response from any controls etc. Finally, I rolled the game back to... 6.3 (I think) and it looked great: The intro video played well, the simple 'mouse-only' control scheme that I wanted to use was working, and the title screen was just right - I could even change the flags at the bottom of my screen to my preferred language. However, the game will not recognize any of the campaigns that I own under this version of Proton. I've tried rebooting the system and a few other basic things with no luck.

I want to keep this post succinct, so I will stop there. I'm sure that a fair few people have played this game on SD, and I would like to be able to also.

For me the most stable setup ended up being Proton 7.0‑6. Not perfect, but at least the UI wasn’t broken and the campaigns actually showed up. Proton 6.3 looked great visually, just like you said, but it also refused to recognize any of my DLC.

I just wanted to thank you for posting; I will try what you recommend. I've placed this question in at least four different places, including official Slitherine tech support threads, and you are the only person to give me any feedback. I know that a fair number of people have been playing this on Deck, yet no-one wants to contribute.

For me the most stable setup ended up being Proton 7.0‑6. Not perfect, but at least the UI wasn’t broken and the campaigns actually showed up. Proton 6.3 looked great visually, just like you said, but it also refused to recognize any of my DLC.

I did some fiddling today based on your input, and I figured out what the problem was. Basically, it had to do with control modes.

So, I used 7.0.6 as you recommended. As you said, earlier versions don't recognize your purchases and later versions have problems with the intro video. 7.0.6 works fine with the videos, so I used that and then disabled the intro video in the options. Several times, I had seen an option to press 'y' to change control modes. I mistakenly thought that that meant the y button on the Deck, but it meant the letter y on the keyboard. I genuinely didn't know that the game had control modes because I've never tried to use a controller on PC. Once I set it to mouse mode, all was well. So, I bound the letter y to the Y key, and when the game goes to the title screen I hit B (escape) and then Y (letter y) to switch to mouse mode, which fixes the screen, control and language issues that I was having. I assume that Steam convinces OoB that a controller is plugged in every time the game starts and I don't know of any way to start the game in mouse mode, but this is good enough.

I still don't know why older versions of proton can't find my DLC as they start properly, but I'm just glad that the game is playable now. I wanted to share my experience in case others find it helpful. Again, I had never tried to play the game with a controller, so I had no idea that the game looked very different when played with a controller vs mouse and keyboard. I plugged a controller into the PC version and replicated the experience that I had on Deck, so that explains it.

JustJeff88 wrote: ↑Sun Mar 15, 2026 9:25 pm I know that this game isn't young anymore, but I have been trying to play it on Steam Deck and it's very frustrating. I have checked Steam forums as well as ProtonDB, but in the latter case the last updates are 5-7 years old.

So, I tried playing on Steam Deck with modern versions of Proton, and there were always screen issues: menu text running together, improper resolution, no response from any controls etc. Finally, I rolled the game back to... 6.3 (I think) and it looked great: The intro video played well, the simple 'mouse-only' control scheme that I wanted to use was working, and the title screen was just right - I could even change the flags at the bottom of my screen to my preferred language. However, the game will not recognize any of the campaigns that I own under this version of Proton. I've tried rebooting the system and a few other basic things with no luck.

I want to keep this post succinct, so I will stop there. I'm sure that a fair few people have played this game on SD, and I would like to be able to also.

For me, you need to Switch to GE-Proton (latest 8 or 9 series) and add PROTON_USE_WINED3D=1 %command% to your Launch Options. This is currently the "Gold Standard" for running older Slitherine/Matrix Games titles on the Deck.