A more thorough investigation has revealed that something's wrong in the PNG files that Adobe Illustrator exports. The same images reencoded with Paint.NET work just fine, and are half as large.

I have tried hard, but I cannot comprehend why one line, which is either love.graphics.setBlendMode("additive") or love.graphics.setBlendMode("replace") -- or "alpha", "screen"... causes this much chaos: https://love2d.org/imgmirrur/XiKJnYw.png https://love2d....