This is a Retail CD-Key for Steam. Which means you can activate deleted Active Shooter game on Steam, which will show in your library.
Since the game got removed from Steam before its release, after keys activation you will not be able to download the game. It will activate and show in your Steam game’s Library only. This is usually the best buy for collectors on Steam. Again, this key does not include game nor gives access to the current stage of it. You will not be able to “idle” it either.