How to make Sonic Mania full screen on Steam Deck

How to make Sonic Mania full screen on Steam Deck
Photo by Ben Griffiths / Unsplash

If you've installed Sonic Mania using Heroic Launcher then you'll quickly realise that it launches in a windowed version that fills about 50% of the screen. Seemingly changing the in-game settings causes it to crash with a 'black screen of death'.

There's a fairly simple fix however.

You need to edit the settings.ini file located in:
Home/deck/Games/Heroic/Prefixes/Sonic-Mania/pfx/drive_c/users/steamuser/AppData/Local/Sega/SonicMania

Set the following:

windowed=n

exclusiveFS=y

Save the file, relaunch the game. Sorted.