Creeper World 4 is fun and not terribly long. It is basically a tower defense game, but instead of guarding a set path toy build towers to defend against, then push back, physics simulator liquid that kills whatever it touches.
Shadow Tactics: Blades of the Shogun, you play a small group of ninjas (and a samurai) in a top down stealth game. Takes place in feudal Japan and you assassinate your way through the plot.
Superhot. FPS with a weird plot about VR and a rogue computer program. The gimmick is if you stop moving, time stops around you (almost), allowing you to slow down and plan.
Lastly and is a game called Soccer Kids Alpha. It is literally the alpha version of the game so it is SUPER short. It is a turn based soccer game, but without the grid based system that some other games use. The alpha is great and we’ll worth the very short time it takes to finish
Not my GPU but my friend’s. He has nothing but good things to say about it. $600 USD which translates to ~£540, but obviously buying it over there the price might be different .