All of Our Friends Are Dead is an indie jump-&-run horror game by Amon26.
You are using [A] and [D] to move left and right. With [W] you can jump. With your mouse you are aiming and firing your characters gun. There are arrow patterns which give you a boost while jumping. With [F5] you save your game and with [F6] you load it. You will need those two a lot.
You are playing as a white thin person, who has to fight his way through a hellish realm. While you go further you encounter morbid creatures.
It is nothing known about the character you play nor the creatures you encounter. Maybe the creatures are demons, maybe monsters or even aliens. It lies in the view of the player.