How Come Undertale Isn't Full Screen?
Sometimes, it's just about hitting the right key. Pressing F4 should do the trick for getting Undertale into full screen.
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Undertale not being full screen is usually because the game defaults to windowed mode. Try pressing F4 to toggle full screen!
It's not full screen because the developers chose it as the default setting. You can easily change it by pressing F4.
Honestly, it's probably your settings. Hit F4 and it'll go full screen immediately!
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