Moonkeys from Mars

You are the lone guardian on a moon base being attacked by angry moonkeys. This was my first attempt of building a game in Unity. Inspired by simple top down shooters. The goal was to make something from beginning to end. Use the arrow keys or A and D to rotate around the base. Use click to fire at oncoming enemies. Yellow enemies are fast and weak, where as Green enemies are slow and tough. How many can you clear before they wipe out your moon base?