You can go fullscreen in the settings tab. Click on the trilobite in the bottom left while in the overworld to open the inventory, and then select the settings tab at the top right!
Awesome. Glad I was able to help in that regard at least! Also, one more quick question. Is this an h-game? I don't really care if it is. It doesn't bother me. I downloaded it because the gameplay looked interesting, I'm mainly asking so that I know whether it's safe to play it if other people are in the room. Roommates don't care if you have scantily clad anime girls in the living room. Roommates do care if you have hentai in the living lol. I didn't notice anything on the about page differentiating either way.