I really like the concept of 1 bullet at a time, but implementation is pretty poor. Your graphic is nice, level design is pretty good, and the music sounds cool, but the game is too difficult in the beginning, it's pretty hard to take the bullet (try to make collision bigger), there is no mouse, so click play button is a real challenge and also I this game really needs score, because it motivates player to play more. But as far as I understand, it is your first game jam and you don't know Unreal Engine well so far (I also use Unreal Engine), so this is a pretty good result for the first game. Keep learning Unreal and good luck)