Zombie Invasion!

Hello fellow developers! About a month ago a friend and I discovered the Unity Engine, and decided to make a simple game to get familiar with the engine. I just uploaded the game to Kongregate, and I would like to share it with you guys. All criticism and feedback is welcomed and appreciated!

Click here to play @ Kongregate.com

As you say it is quite a simple game. I quite like the health bar turning red from both ends and how the zombie sprites are blasted away in stages.