You start the game by dealing 4 cards to each player and the rest you leave in center, this is the garbage pile, but imagine it contains parts of gun you need to build, which is objective of game: "Build gun from scrap", The parts you need of course is A, K, 4, and 7. The two players rush to build gun, whoever builds gun first shoots and the other takes damage. The first one to deal 20 damage to the opponent wins (though this doesn't always have to be the case)
The card game was introduced on the youtube channel Life of Boris