Yes, it’s true that the buttons and checkmarks don’t follow the pixelated scheme, but like in Celeste and other games, we’ve decided to go with pixel art for the game elements and vector art for the UI, logos, etc.
For the Steam button, I’ll make it hide when you click on it. However, I think I’ll leave it on the screen each time you restart or reload the game, because it’s the most important thing for me.