khnut: When I start the game it launches in windowed mode and rapidly flickers between being focused and unfocused. It stops if I leave the cursor still for ~10 seconds, but begins again after any input.
I have tried setting a special application rule in kwin, forcing 'Focus stealing prevention'. I also forced fullscreen, which successfully made the game start in fullscreen, but didn't fix the flickering.

I should mention that I'm using wayland (which is not supported according to the FAQ-page) but shouldn't xwayland make that a non-issue?
I'm also using the nouveau driver instead of the recommended proprietary one, but doesn't this problem seem like it's more front-end than that? Both audio and video seems to be rendering smoothly if I start a new game and wait for the flickering to stop.

Any insight is much appreciated!

27/04/19 EDIT for anyone stumbling onto this post in the future: Wayland was the problem in this case.
I'm not particularly tech-savvy, but what I've gathered from searching is that Wayland just cannot support older games because of how they handle setting the resolution, and because Wayland doesn't like third parties trying to mouse lock. This is apparently not something that xwayland can solve, either.
The only solution that I read about (but never bothered to try) was to run these older games through wine and in windowed mode, but that would also cause noticeable input lag and/or a lower framerate.
My recommendation to anyone like me with a limited knowledge of display protocols and a gaming habit: Use X for the time being, and deal with the screen tearing by tweaking your compositor instead.

khnut: When I start the game it launches in windowed mode and rapidly flickers between being focused and unfocused. It stops if I leave the cursor still for ~10 seconds, but begins again after any input.
I have tried setting a special application rule in kwin, forcing 'Focus stealing prevention'. I also forced fullscreen, which successfully made the game start in fullscreen, but didn't fix the flickering.

I should mention that I'm using wayland (which is not supported according to the FAQ-page) but shouldn't xwayland make that a non-issue?
I'm also using the nouveau driver instead of the recommended proprietary one, but doesn't this problem seem like it's more front-end than that? Both audio and video seems to be rendering smoothly if I start a new game and wait for the flickering to stop.

Any insight is much appreciated!

27/04/19 EDIT for anyone stumbling onto this post in the future: Wayland was the problem in this case.
I'm not particularly tech-savvy, but what I've gathered from searching is that Wayland just cannot support older games because of how they handle setting the resolution, and because Wayland doesn't like third parties trying to mouse lock. This is apparently not something that xwayland can solve, either.
The only solution that I read about (but never bothered to try) was to run these older games through wine and in windowed mode, but that would also cause noticeable input lag and/or a lower framerate.
My recommendation to anyone like me with a limited knowledge of display protocols and a gaming habit: Use X for the time being, and deal with the screen tearing by tweaking your compositor instead.