I liked the game. The art was cool and so was the music.

Suggestions: Instead of having to aim shot and wait for a timer, what if it was just randomized based off a certain sign that appears for you to shoot and then you had to click at the right time for your reaction. 
Overall, nice work!

The concept is very solid along with the art, but the execution is lacking. First off, a reaction game should have a random start, not a count down (like in a race where they have a countdown and then a random start). Also the place where you are aiming each round should also be random. It doesn't make sense to have more than one bullet and also the computer doesn't seem like it will miss after round 5 or so but I didn't test it.

For reference I got killed in duel 8 after 0.5 seconds. If the average human reaction time is ~0.25 seconds then you are giving the player ~0.25  (0.5-0.25) seconds to move the mouse across the screen.  But since the start isn't random you are really giving 0.5 seconds and I couldn't do that even as an experienced FPS player :(

Tbh it was terrifying as the duels went up if that is what you are going for XD 

But touch screens will have a major advantage.