Did you check the options menu? Pretty sure I added fullscreen.
This game in general exists because I was an OC ideas guy for years and wanted to make use of characters with the story being them ending up in a weird world and finding different worlds with clashing characters.
Do you have footage of the vase animation being glitchy? I admit it gets weird when both characters are pushing it.
I've seen seeing tips on how to improve Companion controls and it also depends on either my dev skills or the frankenstein structure of the game.