Quoted from the author's website:

"This is a little ditty I’ve been working on. It’s a 2d sprite-based game system with collision detection. It’s built with custom components, so you can drag and drop these guys onto the stage. I hope to eventually make it so they can be added dynamically, and that there will be more sprite types, like powerups, different enemies, better AI, etc. "

Download the source code of this prototype