I'm gonna send you my honest feedback.
I noticed some issues with your colliders than does not fit the sprites. Game is a bit slow imo, also you should make the player feedbacks more present.
Graphics aren't crazy, but since everything is following the same idea, the whole design is consistent and this is a good point. You do also have issues with layering between some BG soldiers and some scrolling elements.
Your score system with the combos seems to be useless, is there any reason to try to get a highscore? I don't see one.
Unlimited ammo, no dangers, this is pretty easy imo, you should have put some more mechanics into the game like ammo boxes to collect, various enemies...
I liked the global ambience of the war scene and the way the tutorial is integrated into it.
It is a cute short experience, but you should think about a way to make this interesting to replay.