Yes, installing the thing manually and then rebooting worked. I guess its some library that is not included in your game files.
It was pretty cool. Kinda trippy with the constant gradual scaling. The first few times I found myself thinking "Wait, when did I become big??" 😅
Since the scaling is so gradual, there should maybe be some more visual feedback reminding the player if you are currently growing or shrinking, like a little up/down arror next to the character.
Also, I'm supposed to dash-jump with shift+space, but that didn't seem to work. It wasn't possible to jump while dashing. Dashing while jumping worked.