When using Unity, I would set up a desktop app, then set the window to a size that I liked and felt good to play (640x480, for example). After that I would do my web build. Then in itch.io I would set the web window size to what I defined earlier (in this case 640x480). Hope it works for you ;) When using Unity, I would set up a desktop app, then set the window to a size that I liked and felt good to play (640x480, for example). After that I would do my web build. Then in itch.io I would set the web window size to what I defined earlier (in this case 640x480). Hope it works for you ;)