In the game you have to balance the ball on the platform, so as not to fall into the abyss. Good luck in the exciting world of Balance Ball.
The full-screen mode feature that causes this error is temporarily disabled.
If you encounter the "LowLevelFatalError [File:Unknown] [Line: 836]
Rendering thread exception:
LowLevelFatalError [File:Unknown] [Line: 249]
Result failed
at D:/Build/++UE4/Sync/Engine/Source/Runtime/Windows/D3D11RHI/Private/D3D11Viewport.cpp:368
with error DXGI_ERROR_INVALID_CALL" error, then you need to delete the Config folder at the path AppData\Local\Ball\Saved\
UPD: You can switch between full-screen mode and windowed mode using the Alt + Enter key combination
