Thanks for making this - its pretty milk of you sir!
We had fun playing it and everything looks clean, but... it's a little hard to aim (you have to aim like 4 player-widths in front of a moving player). I'm not sure if it's due to the physics based bullet or latency from the network (and I won't invest more time figuring it out - nice obfuscation :) ). Anyway, if it's the physics thing, the bulletmovement could be more visible, if it's the latency, here a crappy idea: What if you perform the hitdetection on the shooting client? I know it's generally a terrible solution (really hackable and lags give advantages), but it would make it a lot more responsive. (Or give us access to the source code, but I know - a lot of work went into it...)
Anyway, cool project!