This is one of those casual games that you can pick up and play whenever you like.

Ever see a portal open up and aliens with umbrellas appear? You will in this game.

As levels progress, more types of aliens will appear and more of them!
You can award yourself a Blue Shield (timed) by hitting a blue umbrella which will protect you against blue alien bullets.
Be warned though, it will not protect against any other color alien bullet or strike or collision!
If you shoot an aliens Umbrella, he'll fall toward you with more fire.

If you clear level 10, then you're seriously skilled. Any more than that and you must be a machine!

Enjoy and have fun :)