What a weird bug! I'm not exactly sure what causes that yet, but I re-built a version with the resolution dialogue* so you can try the game in windowed mode and possibly a more squarish resolution, if that'd fix it: https://drive.google.com/open?id=1txSYikxB2zDBSD9E9feya6-KTse82I_7
* Unity is deprecating the resolution dialogue, which is why it was disabled in the first place. Sadly, we didn't have time to implement a resolution changer in-game!
PS. Sorry about the Google Drive link, but since the voting is still going on, itch won't let me upload a new file for the game ^^'