tangerinagames / super-paper-monster-smasher-starter-kit

The Super Paper Monster Smasher Starter Kit is a side-scrolling monster smashing game. You take on the role of a large green monster which is under attack by a bunch of heros and you have to try and survive as long as you can. Since this project is completely open source, you are free to build on top of it and add your own story, artwork, and sounds and then publish it.