Vampire Survivors is a survival game with elements of rogue-lite and bullet hell. It has a very simple design but is extremely difficult to master.
The player chooses one of several characters, each with their own set of starting weapons and bonuses, and controls them on an infinite stage with an auto-generated, repeating layout. The player's weapons automatically attack, and the goal is to survive as long as possible against constant waves of monsters that inflict damage on contact with the player.
Once you've made your decision, it's back to the killing field to do it all over again, and again, and again, and again, until you've amassed a massive arsenal that spreads firepower everywhere and would be death incarnate if the enemies didn't power up over time as well. The fight has an ebb and flow where nothing can touch you one moment and then the battlefield slowly fills up as you scramble to hold on until the next power surge. It helps that most enemies have only one attack pattern, which is to walk slowly toward you in the hope of knocking off HP before being killed, but that only sounds simple until there are hundreds of them crowding the screen.
Destructible props, usually candelabras, aid in the fight by dropping the occasional temporary power-up. The most common drop, however, is gold, usually in the form of a single coin but occasionally in various-sized bags. Gold isn't spent in the level until a shopkeeper appears much later in the game, but it is used to buy permanent incremental upgrades to the player's abilities between runs. Weapon power, armor, movement and weapon speed, health and health regeneration, and a variety of other options are available, and they stack with upgrades discovered during a run. Gold is also used to purchase new characters, and each of the large cast of heroes comes with its own set of weapons and stat bonuses.
The WASD keys on your keyboard can be used to move your character.