Undertone Continuum was my entry for Ludum Dare 18 (a 2 day game development sprint-competition). It was developed with Unity3D.
You play the game from a first person perspective, and your objective is to protect your base in the middle of the map. Enemies advance from the edge of the map towards your base, and you have to kill them off before they reach their destination. You do this with your color gun, which shoots the colors: Red, Green and Blue. In order to kill an enemy you have to match your color guns color with your enemy. However, not all enemies are red green or blue, some are for instance cyan, and can only be killed by shooting a green ray through a blue enemy (or the other way around, mixing the two colors to cyan, which can then kill the cyan enemy.
It was a fun project, and my first real inking of how code start to become uncontrollable if you just develop with no thought or planning. I also learned that people won't really care to learn complicated controls without a proper gentle introduction or some better adjusted gameplay.