Running a game on mobile makes the images look low resolution even at high resolution. (Native Electron and HTML5 export looks good)
The “Smooth the image” setting is active for all images.
Sakawochi was designed for a resolution of 1600x900.
Your base image size should be a lot bigger so it will not be stretched too much, but rather compressed. It happens too if you resize a window (desktop) whereas it shows as a blurred stretched image, but if you make the image bigger it will show just fine, since it doesn’t stretch it that much.
I already had to shrink the images down in the scene editor to make them fit in the scene.
I uploaded another image of the game exported as HTML5 in the same resolution as the Ubuntu Touch export but this one looks as crisp as it should.