Paper zombies is (as of now) a top-down shooter. It has almost fully functional zombie AI and some simple moveable crates. But we(me and Geemon) plan to have a crafting system, as well as something called rooms, which allow you to do special things in them.
We plan to have vehicles added in, as well as multiplayer support and 3D. As you can see, this is a large project. I have some screenshots on the page for it, as well as a download link.