Vampire Survivors

Vampire Survivors has no right being this addictive. A game where you move and auto-attack waves of monsters should get boring in minutes, but the progression loop — unlocking characters, discovering weapon evolutions, and watching the screen fill with thousands of enemies — is pure concentrated serotonin. It launched the 'survivors-like' genre and proved that a solo developer with a $3 game can compete with studios spending hundreds of millions.