Really nice job!  This was surprisingly entertaining.  The only thing I found annoying was if I shot too quickly, the shots would collide in mid-air and either cancel each other out, or spawn more dudes in the lane since the shots might not have matched.  

Also I was a bit disappointed that there were just 3 levels and not an actual endless mode/harder stuff, but it was still quite good!  Nice job on the everything.

Gets very hard quick, as I constantly have to check keyboard for right key. Nice touch making wrong face stay there as something you now have to deal with.

One complaint tho, because game is keyboard only, would be nice if it was possible to activate next level with keypress.