Unless noted below, all code, art, etc by David Blood.
- Character sprites and animations (Tommy Utah, Zombies, Aliens) by Chris Hildenbrand
- Fire, electricity, blood, gun flashes, etc by POW Studios
- Spinning coins by Clint Bellanger for Liberated Pixel Art
- Blue starfield backgrounds by webtreats
- Throw "swish" sound effect by artisticdude
- Footstep and landing sounds by Jack Menhorn
- Snore sounds by matt
- Levels created with the excellent Tiled Map Editor
Most (but not all) of the above are available under various open / free licenses. See the linked webpages for details.
Also note that some of the art & sounds are temporary and my be replaced in the final release.