https://github.com/ChrisPritchard/Xelmish - contains multiple examples including Tetris and Space Invaders
(Probably needs a bit of a refresh in terms of dotnet core version)
Also have an older platformer here: https://github.com/ChrisPritchard/MiniKnight
And a sort of top down, diablo-esque PoC here: https://github.com/ChrisPritchard/DungeonRaider
And finally, a wolfenstein 3D sort of thing here (using F# plus SDL): https://github.com/ChrisPritchard/tiny-ray-caster