Press the windows key and then click back into it and it'll work. It's the same for all packaged Unreal games.
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I did as you instructed, got me into the game but ended up in some weird shortcut mode, opening tabs, notification windows and cycling through my open file explorers when pressing keys on the keyboard. Disconnecting my keyboard and reconnecting it made it possible to play the game on my third try. I haven't had this experience with any of the other Unreal games in this jam?