Someone is knocking. Count carefully.

Garland Court, 1974. The rent on apartment 4B is impossibly cheap, and on your first night the old woman across the hall slides the house rules under your door:

if someone knocks TWICE — only twice — do not answer. do not speak.

they are not asking to come in. they are asking you to come out.

The woman across the hall has been dead for six years.

Four apartments. Four ways to be afraid.

Knock Twice is an anthology of doors. Each unit of the building hands you a different instrument of dread — and then takes the last one away.

• 4B · fourth floor — the door, the peephole, the chain, the telephone. Learn the knock language. On the fourth night the power dies. On the fifth, the phone learns your number.

• 1B · the basement — no peephole down here. A barred window at street level shows only the shoes of whatever is approaching. Curtains closed after midnight. Shoes tell the truth. Knocks lie.

• 1A · the super's office — the intercom board, one light per tenant. You decide who gets buzzed into the building. Guess wrong and it isn't you who pays; it's a light going out upstairs, and a name you'd learned.

• 4C · across the hall — the other side of the peephole. Someone new lives in your old rooms, making your old mistakes. The only thing you can say through a door is a knock — and you know exactly what two of them means.

The 1-bit limit IS the horror

Two colours. Pure black, pure white. You can never be certain what you saw through the peephole — the aesthetic is the mechanic. No gore. Just silhouette, negative space, and the wrongness of a shape you can't quite resolve.

Sound is the monster

Every sound in the game is synthesised from scratch at runtime — there is not a single audio file in the build. Each visitor has a knock rhythm you learn the way other games teach enemy silhouettes. The mix drops to total silence for two seconds before every double-knock. Play with headphones.

Rules you learn, then rules that lie

The difficulty curve is not stat pressure. It is the steady corruption of what you know. Night one teaches you that three knocks are safe. Later, something knocks three times in the superintendent's voice. Every safe pattern eventually gets counterfeited, and your own knowledge is the resource the game spends.

Features

• 14 nights across 4 unlockable apartments — roughly an hour, longer if it keeps killing you

• 12 endings, including one that closes the loop on the very first note you were ever handed

• Strict 1-bit art and a fully procedural audio engine — zero asset files

• Death restarts the night, never the run. Every note you're given can be re-read at any time

• Full mouse or keyboard. Adjustable text speed, scanlines, and volume

Contains flashing images and sudden loud sounds.