User blog comment:Windindi/Updates To Announce/@comment-190.105.53.41-20150511012417/@comment-3495717-20150511121108

I think he means the engine on which the game is built.

Photoshop blurs the image because of the method it uses, seeing as it is intended for photographs and large images, not tiny sprites. If you scale via image size instead of the transform tool, you can set the scaling method to Nearest Neighbour, which doesn't blur the image.