Escape from Pen Island
We used unity to build a survival-based game set on Pen Island. Think CoD: Zombies but with office supplies instead of walking cadavers, and only 36hrs worth of quality control. The objective of the game is to escape the island by finding the Hexastix portal (Funnily enough, the base shape of the hexastix is a rhomboid dodecahedron, a Catalan solid) whilst avoiding/killing any enemies.
This was our first attempt at a serious game, and it was interesting to explore Unity.