@FlyingTomahawk If your PNGs are pixelated on the edges, you are likely using 8-bit PNG format, this uses a gif style indexed pallet and has no support for alpha blending. This is the default setting on photoshop/illustrator for save-for-web output. Make sure you are saving your PNGs as 24 bit to allow for alpha transparencies around the edge pixels, and the pixelated effect will be gone. Drawback is the file size will be 5 to 10x larger.
Graphic designer by day, gamer by night, haha.