Went for the purist interpretation, very nice! I like the gameplay, and it doesn't take long to figure out the mechanics even without explicit instructions, which is good. It's easy for the chaos to sneak up on you...
One tiny improvement I would suggest is that the main firing button (which perhaps one uses very often :) ) be different from the restart button--a couple times I didn't manage to see my score because I accidentally clicked right after losing.
All in all, fun stuff! Which tools did you use?