It's very difficult - I think making things a bit easier on the player (especially on the first level when you're still learning) would be good (for example, you can be killed almost instantly at the start of the game, which I feel might confuse people).
That said, it's pretty fun - it's a good base for an action game, and the traps & strategically placing them is a cool mechanic :)
Btw, the explosion sound when the guy kills you is too loud, especially in comparison to the rest of the game - adjusting that would be a significant improvement. I also noticed that the exit button when you die seems to freeze the game on the web version.
Good job :)