Download size

How many GB is Do Not Open?

10 GB

That is more than the typical Puzzle game, which needs about 3 GB.

Leave at least 17 GB free: games need headroom to unpack updates.

The figure is the storage Steam lists as required for this game, not a measured download.

Survival horror game Do Not Open is a mix of escape room elements, plus it's said to be based entirely on true events. You're playing for Michael J. Goreng, "a well-known zoologist and epidemiologist imprisoned in his own home, where his wife and daughter are held against their will".