Complex game templates have a handy Photoshop reference file you can download to help you design your game. Simple effects and games do not require a Photoshop reference file..
Each Motion Maker template has a different image size restrictions. Generally, your images can be a max of 1920 x 1080. The templates are setup to accept 4:3 or 16:9 images.
For graphics uploaded as particles, it’s recommended that you save to a format that allows you to save the image with a transparent background, such as png.