Use your CD key on Steam.
Monstrum
If you do not have a Steam account, you will need to download the client from the official website, install it and then create your account. Once you are logged into your account, click on "Add game" in the bottom left corner and then on "Activate product on Steam". After a few clicks on "Next", you can finally enter your CD key, the game will automatically be added to your library and the download will begin.
Steam EUROPE
CD key to use on the GOG GALAXY client to download your game.
Monstrum
To activate a game you download on GOG Galaxy, open the application on your computer, log in to your account, click on the menu icon, and then select "Game Codes". Enter the game code in the appropriate field and click "Continue". Once the code is verified, the game will automatically be added to your GOG Galaxy library where you can download and play it.
(*) The best price is currently $1.96. We discovered this product available from 16 vendors supporting 5 DRM systems: Steam, GOG Galaxy, Xbox Live, Nintendo eShop & Sony PSN on 5 platforms - PC, PS4, Switch, XboxOne & Xbox Series X. The game comes in 2 editions. Our price comparison tool has identified 23 digital offers. and 6 prices for the physical version.
Monstrum
Monstrum takes the traditional survival horror formula and remixes it completely with procedurally generated levels, permadeath, and AI driven predators, ensuring that nowhere on its derelict cargo ship is ever truly safe.