After comparing a few fast browser games on mobile, I think simple endless runners are useful for checking touch response because small delays are easy to notice. I used slope as the test case because the controls are easy to understand, but the speed ramps up quickly.
On Cubot phones, it felt smoother when browser zoom stayed at the default level, heavy background apps were closed, and battery saver was turned off during short play sessions. Landscape mode also helps because there is more room for left and right movement.
