An interesting take on the them. Some visual feedback on how much damage the satelites were taking would be nice, so when multiple ones are being attacked we can evaluate which one to defend first. I like the variations on the weapons. The music is nice. A very simple pause menu would be nice (although this stems from me trying to eat soup while playing... ^^) Astroid like controls are fun, however a slightly reduced turn speed would have been nice to allow slightly more control with the arrow keys. Great job with the graphics too. I like the particle effects and the music fits the visual style. Finally, I am a big fan of integrating the tutorial into the game, so the start is a big plus for me.
Overall, a solid little game that has provided me with 10 minutes of fun! Good job :)