I had an issue with fangames such as Shining Shooting Star being unplayably blurry. I've found a fix from trying to find a fix to solve text blurriness in League of Legends.
Note that this guide only applies to Intel Graphics.
1. Open your Intel Graphics driver.
2. Go to 3D:

3. Turn on Custom Settings. Set both dropdowns to "Application Settings", and "Application Optimal Mode" on:

You should no longer have unplayable blurry games.
Demonstration with Bullet & Music ~ Barrage Musical.
Default settings, 3D preference = preformance

Custom, "Application Settings" on
