Idle Slayer is an auto-runner with idle game elements, with a fantasy setting and a retro pixel-art style. Run and jump to grab coins and cut through enemies to earn riches, upgrade gear and unlock skills. Once progress begins to slow down, the player can "ascend" which will reset the game but earn special Slayer Points, which can be exchanged for permanent upgrades that significantly speed up the next run, through a special skill tree.