Here's the second prototype, tried to strengthen some of the things people liked and evolved it:
http://anamei.net/files/ONA/WebPlayer/WebPlayer.html
I'd like to hear feedback on this - what you liked, what you didn't like, what you wanted to do, etc.
Controls:
I've added a second type of turret that is very heavy and takes the collisions better.
Guns are still really weak on purpose, so you get to see how things interact (they will do a lot more damage later, but cost to build of course.)
You can highlight and select turrets by holding SHIFT or drag-selecting, and then aim them as specific asteroids.
You can use the standard RTS control groups (Ctrl+1 to set group 1, press 1 to select those, etc) for those turrets. (Turrets that don't shoot can't be selected.)