Double Death is an arcade-style zombie survival and beat'em up game in the vein of old-school sidescrollers, with influence from modern survival games like Killing Floor. Double Death has an extremely fluid modding API as well, which allows for almost every aspect of the game to be customized and added onto, including custom maps, gamemodes, zombies, and more!
Been working on Modding Tools lately. Here's a WIP of the in-game Map Editor. No, I'm not dead.