a character draw with the pencil brush: you can turn anti aliasing off completely and produce this SNES esque style in photoshop when using all tools, and the pencil tool is pretty much designed for such things. Or use a format that supports better transparency, such as TGA or PNG (depending on what your engine can handle-…
Yep like arrangemonk hinted at you're using a 1 bit technique meaning your transparency will either be on or off, no blending. You can't have a purple pixel and expect it to be partially transparent. If you sample the pixels around the edges of your image they are not exactly your transparent color. To fix this you need to…