I have updated the report with multi-monitor results and a better resolution fix. I have set the multi-monitor and ultra-widescreen grading to Silver due to not being able to select the resolution properly.
THE INTERNET wrote:
It's a bit strange that the first I launched Tembo it started up in fullscreen 5x1P Eyefinity 5400x1920. After that it has never worked in fullscreen correctly again. Now the highest resolution I can get it to work is windowed 1920x1080. In full screen it will smash itself into one monitor and duplicate on the other 4.
This isn't the only game that has given me this issue and hopefully there is some kind of a fix for it.
This game sets the resolution to the current desktop resolution the first time you run it, so if you change the in-game resolution option it will use that one instead; that's why you weren't able to get the resolution again. Forcing the resolution as described will work.
This same method works for most other games using the Unity engine, but some will reject resolutions the game doesn't specifically support.
EDIT: Reworded widescreen method mentions.