I’ve uploaded a patched version of Deathbeam! It offers a big performance boost, rendering and collision fixes, and tweaked scoring. After I released it I found that it got horribly chuggy on pretty much any computer but the one I developed on (except when I was in OS X… weird).

This should not be considered for voting, of course!

You can get it here:
Windows: deathbeam_p3_win32oo.zip Mac: deathbeam_p3_osx.zip

And Python source is here. If you go that route, I recommend running it with python -OO deathbeam.py.