I started playing with a small real-time strategy game in Unity. You select a survivor, send them around the map, and try to deal with the zombies wandering in. Very much a prototype.
The unit logic is written in C#, with Unity's NavMesh agents handling movement. There are separate behaviours for survivors and zombies, and mouse and touch input for selecting things on the map.
Survivors can shoot at targets, while zombies lurk, wander and chase survivors. The bullets use an object pool so they can be reused instead of constantly creating new objects.
This is mostly an experiment in unit controls and enemy behaviour. There are notes in the code about gathering resources and building defenses, but those are ideas rather than a finished game.