Interesting little game! The WebGL menu is a little squished in the window. I found that enemies didn't seem to die as quickly as I expected them to at times, where they seemed sort of bullet spoungey before dying, especially with dual pistols.
The collision on the platforms is a little wonky too. I kept getting stuck on the sides of objects trying to jump on top of them, and sort of studdered my way down the wall. Not game breaking, but noticable.
At one point I was pushed off the map and respawned in the most interesting of locations:
voxelmob.png
They just kept spawning and then some of them to the left kept exploding off-screen? By the time the FPS was down to about 10, the group was a giant mass of green and red squares, and I no longer had to hold down the mouse button to keep firing.
Otherwise, a great start to something much bigger, and I'm glad you already have plans in the works! Great job!