Steam says the key has already been redeemed. This sort of thing hadn't happened before, so I tried to see if SG had some sort of PM system since it seems you can't message non-friends on Steam, and, well now in retrospect leaving a comment on the giveaway seems like a way that'd have worked. I generally don't have much need to contact people here or on Steam, so my apologies for consequentially not being great at figuring out how to do so.