Had a lot of fun with this game, I ended up building a scene and level controller to time delivery of the various enemy fleets and upgrades. I decided to use different particle systems to show player health and swap them in and out as health changes. Learnt a lot in putting some polish into the game which is if course the point of doing it 
I wrote music and most of the sound effects with Logic Pro. If you are interested in a copy of the m3 for your game let me know.
