I made a gaming control panel using an Arduino Leonardo to play simulators. Currently using it for DCS World, but it should work in most games just like any joystick / gamepad.
Convert N64 Controllers into USB Gamepads using Arduino | Freetronics
Arduino Leonardo/Micro As Game Controller/Joystick : 10 Steps - Instructables
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Arduino Leonardo: Specifications,Documentation and FAQs
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Add USB Game Controller To Arduino Leonardo - Micro - 9 Steps | PDF | Arduino | Office Equipment