Even though this was short, this was FANTASTIC! There was something SUPER satisfying about shooting the rocket or super gun, and there was all these nice touches like the ships looking electrified (which from what I can tell is purely a visual effect) - great work.
Also, I don't know if this was intentional, but it seems like the mid-game 'interludes' always seem to come when I have this awesome multiple gun upgrade-powerup thing going on - I figure it is the AI's way to let my timers run out before deciding to attack again ;)
Some tips: Someone complained that you can shoot at where the enemies spawn at and not collect the energy things. Turns out that your mouse tracks off the screen with you if you are clicking. Also, the ground off screen seems to continue to slope. Since certain powerups (air defense/rocket launcher) will happily kill enemies off screen, just remember to periodically do brief off-screen swipes with the mouse to collect all those lost orb things ;)
MAN! What a satisfying game! Pew Pew Pew! :)