The idea and music is pretty good. Sadly the game is really unpolished and it is really difficult to see what is happening. 

i would have liked to play the game more, but the movement was really jarring. the enemy sprites were also very shakey.

I feel like it's not following the theme. I mean, the target may be invisible, but the red line makes that unnecessary...
The fighting is somewhat good, but because I can't run and attack at the same time it means I often get hit. More often than a rogue should, at least.
I think it needs some improvements... the music was good at least!