yep, try to contact him though

sounds like you got the DLC, which would show up if you actually had Dwarfs

Right click on the game, click on "properties" than go to DLC

well it looks like he gave you wrong code by an accident... so definitely contact him, give him time and if he won't resolve this issue, mark gift as not received and live with it

if it is a dlc it wouldn't have even let you add it since you don't have the base game

The best thing you can do is send a ticket to support. They're usually pretty quick about matters like this.

update : guy said via email "man must relog steam :D steam after this show in your account :p
ok dont remember click received gift :D" and later told me if I wanted a compensation key from the IR/IG bundle...

I won a copy of Dwarfs!? including DLC and when I check my account history, it's also listed as Dwarfs DLC comp. Maybe you've got the full game including DLC?

I won a copy of Dwarfs and it doesn't even work!