I agree on the sensitivity part already mentioned, it was difficult to aim properly. Interesting take on the theme as it actually turns the suggested perspective around. The terrain is IMO a bit too hilly as the participants can easily take cover behind a mountain. A little scaling down the height might already do the trick here.
You mention some assets you used in the game on the description page, and I searched for the first sound effect. Please look into all the licencing stuff some more - this sound effect, for example, is available under the terms of CC BY-NC 3.0, which means you have to give attribution (name the creator) and link to the licence. I didn't check the other assets, and while there are a lot of people that just use those assets and forget about it all together, try to get it right.