So I tried your game for a bit and this is what is something I suggest.
1. In your tutorial I feel like all the info and controls are thrown at you a once like a truck instead of slowly showing what each thing is.
2. In the menu the music kept resetting every time I pressed a button. (Im sure this is a bug)
3. I wish there was some way to at least lower/ mute the music, because I didn't really enjoy it.
4. In the inventory you should be able to rotate items for example a gun in the backpack.
5. When you jump it feels like it's a little bit too high.
6. Hope you add a sight on the AR-15.
Don't take any of this to heart this is just my feedback.