lavbubl it has to do with how the alpha values of the sprites are rendered.... a new alpha image is created each time to my knowledge that is, by doing this yourself you can save yourself the headache, sprite opacity is the most demanding besides tinting the sprite which isn't as costly usually that is.... either you generate your own images manually by applying opacity beforehand or make your own library that applies opacity to sprites correctly rather than each rendered frame, also do note that applying opacity to 1 sprite doesn't impact it as much you should only really start to notice if you had a group of multiple sprites with applied opacities
