Black King's Gambit ???

I was researching King's Gambit opening for white, and for some reason decided to toy around with some strange behavior on blacks part.

Fortunately I was lucky to win - but I don't think I'll try this defense again :-)

I wouldn't really call that a reverse king's gambit. That's more of a reverse scandanavian or something. Google says 1. d4 e5 2. exd4 is the Englund Gambit, and 2. ... f6 is considered a variation of the Soller Gambit, for whatever that's worth to you.

If your opponent plays 3. e4, you are in a lot more trouble. Your development is cramped, you are down a pawn and you can't retake on e5, because that drops a rook to Qh5+ (g6 is forced, then Qxe5+ wins the rook in the corner).

But that's the fun part of playing unorthodox gambits in blitz. Your opponents often don't take advantage of it and you end up with a whacky game.

11. ... d6 hanging the pawn, white can just play Nxd6, instead, white ignores it and hangs material himself, 12. Nf3 handing over his knight on f5. 

The closest thing to a King's Gambit played from Black side is the Latvian. (Although the tempo makes a significant difference.)

I think GambitKing is on his way here.

pretty cool endgame

Yep, the closest thing to the King's Gambit with black is the Latvian: an opening which you really need to know the lines if you want to play with any actual success.  As Gambitking's games show, their truly headspinning (in a good way).

I'm not sure I like this opening schema at all.  Especially after f6... black just doesn't look particularly well off.  Speaking about Gambits against the QPO, the only one that I know of which recommends itself is some variation of the Benoni, which invites the Benko Gambit.