/The king can move 1 square in any direction./I played the game, I know it was checkmate.
Lol :) Simple Wing gambit transposed :)
White's third move was a tactical blunder and black should win at least a piece beginning with 3...Qf6. The rook can only be saved by 4 Nc3 which is vulnerable to 4...cxb4
Just d4 defends?
Yup. As little as White gets for the pawn after 3...cd, he gets even less after 3...Qf6!
I would go so far as to say that this gambit (Newfoundland gambit I call it, where I am from) will work where White is able to reclaim the lost pawn. I am not expert nor pretend to be but I do believe it is a valid move.
It looks like a normal gambit to me.
I don`t know it by name but sacrificing a pawn in that fashion is very common and normal.
It may not be the best possibility in that exact position but if you play it in all sorts of positions you will eventually get the hang of it.
Just like in the Sicilian an exchange sacrifice on c3 is normal even though in some positions it not the greatest.
I thinks its good to have these sacrifices in your mind so you can play them when you feel the timing is right.
Well, the timing and exact position is the only important thing. It's no good if you have the 'right idea' but actually it doesn't work in the position, you're just a pawn down.
Maybe you can try 5.d4 Be7 6.axb4 Bxb4+ 7.Bd2 Bxd2+ 8.Nxd2 O-O 9.g3.
rook takes a7