Press green flag, wait* till the image is rendered, then* move your mouse on the stage (wait a bit, till you move it again for the image to render). Its rather slow, you might want to try it on turbowarp: turbowarp.org/1014000233
I fixed the mario map test. The problem was that the blue channel was too intense and the red channel was inverted. The difference is unnoticeable though, so I zoomed in to show that it is now fixed.
