Undead Invasion is a roguelike zombie survival game built as an HTML5 browser game. Released in 2024, it places you in the role of a lone post-apocalyptic survivor defending a ruined orphanage against escalating hordes of the undead.

The game combines side-scrolling shooting with defensive planning — you fight zombies with firearms, melee weapons, and grenades while placing barricades and traps between waves to slow the next assault.

The core loop is brutal and addictive: survive a day, earn coins, buy upgrades, and prepare for an even harder tomorrow. There are no checkpoints. Death means starting over completely, which gives every decision real weight.

With its pixel art style, diverse zombie types — from fast crawlers to armored brutes — and a deep weapon and trap system, this free online game delivers high-stakes survival action that rewards strategy as much as reflexes.

The game also features two modes: a main survival campaign and a Playground mode for experimentation.

Undead Invasion uses a keyboard-and-mouse control scheme on desktop: On mobile, the game uses virtual on-screen controls including a joystick for movement, weapon switch icons, and tap-to-shoot mechanics. Undead Invasion structures gameplay around a day-night cycle.

Each new day brings a wave of zombies that is larger, faster, and more dangerous than the last. Your objectives each day are straightforward: This loop continues until your character is finally overwhelmed and killed.

Since there are no checkpoints, every run starts fresh from Day 1. You have access to multiple weapon types including firearms and melee weapons.

Ranged weapons let you pick off zombies from a safe distance, while melee attacks and kicks serve as your close-quarters emergency tools when undead breach your perimeter.

Grenades are your crowd-control option — save them for moments when zombies cluster together in tight groups for maximum efficiency. Maintaining distance is critical. Zombies deal damage when they get close, so constant repositioning while shooting is essential.