the game is really fun, I liked how "arcady" it looked. like others I accidentally killed myself at the beginning, but I understood how to play on my second playthrough. Its pretty addictive to zap an entire mob X)
I think it would be better with more kind of humans with different behaviours, or if it was a bit harder (to accentuate the retro and arcade aspect of it).
The music is nice too, well done !