To play 'SUPERHOT' in a resolution different from you monitor's native resolution, you simply have to change it from the windows 'Settings' app instead of the launcher. This can be done by following these steps:


STEPS:
1. Launch the game from 'Steam'. The launcher will pop-up.
2. Open 'Settings' by pressing Windows key and the letter I key together.
3. Navigate to System/Display and find the 'Display resolution' option. Select the desired option.
4. Immediately after that, press 'Alt' and 'Tab' to focus back to the launcher and hit 'Play'.
5. After exiting from the game, change your resolution back to normal.

Make sure that you prevent Windows from focusing on the desktop when you lower your resolution. Else, it might end up changing your icon arrangement and messing up 'Rainmeter' if you use it.