13 AM

13 AM is a tower defense game about surviving an impossible hour in your home. When the clock changes from 12:59 AM to 13 AM, a strange eye appears on your computer screen and warns that Visitors are coming. Using a security program, you watch a camera feed and deploy holographic ghosts to make them disappear while speaking with the eye.

Defend your home

You place ghosts in a hallway to stop Visitors reaching your house. The Luminous Ghost lights the hallway and generates plasma; when it turns black, click it to gain one plasma point. You spend plasma to place ghosts. The Orboo fires energy orbs at Visitors, so placing it farther away lets it attack from a distance. Any ghost touched by a Visitor disappears, making placements near the end of the hallway riskier. More ghost types unlock as you progress.

Twelve levels

The game has 12 levels, each lasting 5 minutes. You begin each one with one plasma point and no ghosts in the hallway. Visitors arrive throughout the level and grow tougher and more numerous over time. You do not need to defeat them all, but if one reaches your house at the end of the hallway, you lose and must restart the level. The game saves your progress automatically, so you can continue across multiple sessions.