Steam keys

[Caterpillar]

Me instead I have a Penumbra Collection serial number, it should came from a "Indie Linux games pack". I don't know how to use such key to enable Penumbra series games into my Steam account

[Romulator]

Follow the Redeeming Steam Keys steps as seen here. You will need the serial number for the Penumbra Collection, which should be found with your Humble Bundle purchase.

[Caterpillar]

This is very strange, on Humble Bundle website I can only see Penumbra overture, not Penumbra collection. On esellerate instead I have the Amnesia game, and again no Penumbra collection...