This game is 'Children of the Sun'. Developed by René Rother and brought to you by Devolver Digital aka. mad lads who brought us Hotline Miami, Katana Zero, Mother Russia Bleeds and more bangers.
Children of the Sun is a puzzleshooter where you control only ONE bullet you have to take down the whole pack of cultists. You must plan carefully and use every trick the game presented to you to make sure no cultists made it out alive.
You can try the demo of this game right now on Steam.
P.S. Please don't do drugs. Or join any cult. Just don't. Play games. Stay healthy.