Thanks for the feedback.
RE: Energy
The weapon and shield energy is the same. You have to balance firing against shield strength. Sometimes you need to stop firing and duck and dive a bit to recharge. You can read up on some tips in the game manual (in 'Start Menu/Suisoft/Starfire - Ares Assault'). I'm going to put the manual on the website when I have styled it.
RE: Boss from bottom of screen
I have wondered about having a warning message flash up a boss is coming. Also, some players have respawned and crashed into him so I think the respawn invulnerability delay needs a tweak.
RE: Flipping player ship
It's a nice idea (reminds me of Uridium) but would change the gameplay massively, particularly due to most enemies spawning at the top. I am considering a free roaming shooter where flipping could be an option. I need to make a decision which game to do - some many ideas, so little time!
The trick with the first boss charges is to anticipate the waves using the musical cues and weave through the open space to get into position.
An Italian blogger posted up a gameplay video that shows how to splat the boss:
http://www.youtube.com/watch?v=ZJzyB2Sll4A(about 1 minute 40 into the video the boss comes in)
RE: Slowdowns
I'm going to give priority to optimisation and have some detail settings in the game. It's very odd, as my development machine is 4 years old and the game is 100% smooth at 1680x1050 resolution.