Reverse pongineer

This game is created from scratch like the old, well known pong arcade games. Let's see what can I do to make it more fun. 

The basic idea is to be able upgrade the balls and the pong stuff, to eliminate the bricks and alien space ships.

The story in a nutshell:

Our solar system is attacked by aliens. They want to invade our planet, but our space-station is on the front line of the war. They trying to enter to the space station, to crush the shield generator of the planet. The only way to penetrate in our defense system is to capture the external docking station. The invasion was not expected and just the workers of the docking station can hold back the waves. They can use as a weapon, what got in the storage. They have to hold on until the reinforcement arrives. All hope of us in you to use the stuffs to protect the shield generator. Good luck!

I'm using the Unity game engine for development and C#.