itch.io

pressing windows+shift+left/right arrow keys will fit it correctly. 

Normally that shortcut is meant to transfer apps to different monitors, but i found its quite useful when fullscreen games dont fit right by themselves

fire

Great game, absolutely love it! The only bug that I've noticed is a crash when I put a merger on the letter box, try to tie them together, delete the merger and try to tie a merger from anywhere to that box.