Adding your own Sprite Tutorial
From Shoot Em Up Kit
To add your own sprite to a project in the Shoot 'Em Up Kit, place the sprite in the project texture folder (Shoot-Em-Up Kit Projects/projects/[project name]/textures)
Open the project in the Shoot 'Em Up Kit and go to the Sprite Editor
Select Create New to add a new sprite
In the Sprite tab you can set the name and size, whether the sprite has transparency and whether to create an Entity (objects that can be used in the Level Editor as Players, Enemies, Scenery etc.)
Next, go to the Texture tab and click on the texture box. This will bring up a list of all available textures including the one you added to the textures folder. Select the new one and click OK.
The sprite will now be available in your project, and if you checked the Create an Entity box in the Sprite Editor Sprite Tab, it will be available to place in a level