If you’re using Mac, the FN and F4 key combination is typically used to switch applications from a small screen to full-screen mode. However, like the previous method, this method only works for Windows operating systems. After that, Undertale will enter into fullscreen mode. To use this keyboard shortcut, press and hold either Alt key, and while continuing to hold, press Enter. Press the ALT and ENTER Buttons SimultaneouslyĪlt+Enter is a keyboard shortcut most often used to switch the application to the full-screen view.