- run the game (it starts out running fullscreen on my leftmost monitor, which is, unfortunately for fullscreen games, my 1080x1920 portrait monitor that I use for pinball)
- press alt+enter to get a 1080x1920 window
- drag that window onto a normal landscape monitor
- press alt+enter again. now it's fullscreen on that monitor
now I can play the game as intended! pity that I won't have time until Monday
