How does your submission match the theme?
Movement also servers as an aspect of attack. As you move you release particles that damage enemies in the opposite direction. Health is also duel-purpose in that the lower your health is the less projectiles your release, making it harder to defeat enemies. The game also stays simplistic by using a single button, the mouse click, you move by clicking on the screen in the direction you wish to move.

Third-party resources
Engine: Unity
Art: https://www.assetstore.unity3d.com/en/#!/content/73949
Volumetric Lighting Script: https://github.com/SlightlyMad/VolumetricLights

All either Open-Source or free use.

Contributors
Only person who helped was a friend of mine who just made sure the build worked on Mac, since I don't have one. He didn't participate at all in the creation of the game.