I was asleep at that time, otherwise I would have been able to help out.
You can Reload by pressing R. The Box in the middle of the screen is a vignette effect that didnt scale to your resolution. Currently the engine doesnt support 21:9 or 32:9 or 4k Resolutions. The Ammo went out because you didnt take the pickups^^ Thanks for playing! I see I should add some hints to the game at the start.