Hey, this wasn't overly critical at all.
The pin icon locks the window to the foreground (so it can be on top of other applications).
I've noticed that sometimes indeed the song UI doesn't update. Just reopening the window should correctly show the UI then. This is something I'll probably fix soon.
Emotions and facial expressions is what I'm currently working on, because she's too static indeed now. This project is mainly made so I could learn 3D and Unity a bit better, so it may take some time to get this perfect.
The game's you're talking about is what I'm currently implementing, where she can play a simple version of rock paper scissors with you (and winning gives you some more friendship points). Right now it's only gained by idling, but I want to expand on this by indeed playing with her, feeding her or interacting with here in some other way. The backgrounds are 2D currently, and I had a fullscreen mode in a previous build, maybe I'll add it again at a later point, but I wasn't really happy with it.
Regardless, thank you for the detailed response! It helps a lot in figuring out where to go with this game, as I made the game in 3 days over the holidays. I'll keep pushing out updates and adding more content/progression to the game over the next months,