I've finished the "Clear the Level" game mode. Added some music, thanks to Kevin MacLeod of
http://www.incompetech.com He's got some great royalty free music for games. Also added a credits screen. I had some problems but finally got the html5 project to compile. It works on the Chrome browser, but I get a typed array error on Firefox and IE. It's not finished, but a playable demo here: Trouble with Tribbles playable on Chrome only so far.