I really like the idea in concept but I was having performance issues which made it difficult to judge properly.
Some constructive critique:
Menu - The return to menu button in the help section is hovering over the objectives text which makes it difficult to read.
Game - I was personally having some issues with the performance of the game. The frame rate was quite low and everything was very choppy. This made it quite difficult to play and I wasn't able to ever get passed the first level. Not sure why that would be happening. Other than that I think it would be nice to have some sort of way to gauge the radius of the enemies search so you can better navigate and plan your route.