If you find the image too blurry, try to raise the resolution that you run the game with. Recommended resolutions are 1280×1024, 1600×1200, 1920×1440. The higher the less blurry the image will be. Higher resolutions cost performance though, of course. You need to find the right balance for your PC and the game you try.
For the fully native 4k resolution of your Pimax the game resolution would need to be even higher than 1920×1440, but that would bring down almost any game to its knees.