Great idea, although it's not very much right now.
At first, I didn't know how to zap because it doesn't work very well long-distance, but once the robots get closer, it looks cool.
There's little point of giving you constructive criticism right now, since everything is probably going to change, but well…
– I'd pick better ambient music than a six-second loop – it works initially, but gets annoying quite quickly.
– The game window is quite small; consider adding a fullscreen mode without the IndexedDB part at the bottom.
– I'm not sure if the zap ability works on multiple robots at once; perhaps it should.
– What about jumping? There's a lot of obstacles which would help you slow down the enemies if you could jump over them
– You can fall off the world boundaries, but who cares at this point of development…

I think this would make a really great horror game, especially if the environment was darker and you didn't get the zap ability until later. At one point, I was cornered by the robots and even though they didn't harm me, I was completely unable to move until I blasted my way to freedom. Imagining that, in the dark, with creepier robots; running through a maze of dimly lit corridors, until you reach a large room where you're completely surrounded, panic and learn to zap through – I'd personally consider it far more interesting (and with a story-telling potential) than if it was a simple shooter about zapping hostile robots until they get close and kill you.

Good luck!