Scam or not ?

Hi all, so before 5 minutes I was send a friend request from a Steam user with 3 years of record on steam and only Counter-Strike as a game that was never given for free. The other 20 or so games were given for free in the recent year or 2.
So this kid adds me as a friend out of the blue and asks if I bought my Tropico 3 and if I have a spare key for him (and says some other recently given away for free games like Gun Monkeys that he would like to have).
So I sad no, but I have GM for trade with cards or for some giveaway. So he starts the usual - "you're going to trade a game that was free and bla bla", on which I replayed if he wants to trade free for free Gun Monkeys for Weird Worlds (I can't get that one because of twitter) and he agrees. Next thing when I ask who's going to go first, he started again with the bs like "you're calling me a scammer gtfu bla bla". Then I sad "Ok let me give you the gift first then you'll give me the key for WW" because I don't care for GM and I wanted to see if he was a scammer indeed (I was like 90% sure he is but what the hell).
So I try to invite him for trade but, a plot twist occurs he haven't had 15 days with steam guard and cannot trade anything :D. I unfriended him of course and blocked but does he was a scammer or not? Have you been friended by someone who found you, exactly you of all millions of users who have tropic 3 or any other recently given away for free game, and who begs for free games?