A nice idea, but there's times where there's long gaps between any attacks being sent so it's impossible to win before the hero runs out of stamina

Neat idea. Different movement  and/or attack speeds would make it more interesting. Maybe make the enemy actually movable in 2d instead of having only 3 positions?

the basic mechanic is pretty nice, sounds, graphics and a little variance between the foes would have been cool!

Simple game, I think a bit more mechanics, visuals and sounds could really flesh out the concept

Good idea. I would have liked to see it get a bit further along in development though. 

Simple game,  but that is not necessarily bad.
Good work!