In the following game Black is vigorous in his response to White's gambit. However, he seems to run out of energy at the end. Is being down 5 pawns for a piece reason enough to resign? In this case, perhaps not: Stockfish 8 evaluates the final position as even.
Wall, Bill - NN
1.e4 e5 2.Nf3 Nc6 3.Bc4 Nd4
The Blackburne Shilling Gambit.
The Blackburne Shilling Jerome Gambit.
4...Kxf7 5.Nxe5+ Ke8 6.Qh5+ g6 7.Nxg6
8.Qxh8 is a mistake, but I once managed to win with it anyhow, perrypawnpusher - tampajake, FICS, 2009 (1-0, 12).
8...Ke7 9.Qg5+ Nf6
Better than 9...Ke8 in perrypawnpusher - adamzzzz, FICS, 2009 (1-0, 39).
Better than 10.e5 in perrypawnpusher - JokeritT, FICS, 2010 (1-0, 28).
I faced 10...d6 in a number of games; perrypawnpusher - foreverblackman, FICS, 2010 (1-0, 21); perrypawnpusher - vlas, FICS, 2010 (0-1, 23); perrypawnpusher - theferno, FICS, 2010 (1-0, 28); perrypawnpusher - Raankh, FICS, 2010 (1-0, 49); and perrypawnpusher - michon, FICS, 2015 (1-0, 36). Bill, too: Wall,B - Guest5170841, PlayChess.com 2015 (1-0, 15 ).
11.Qxd4 Qe8 12.Nc3 c5 13.Qe3 Qe5 14.h3 Bh6 15.Qf3 Qf4 16.Qe2 d6
Black is fighting back vigorously, despite his slightly exposed King. Still, I am always suspicious of ...c5 in these kinds of positions, as it can allow further opening of the game.
Qh4 18.Bxh6 Qxh6 19.dxc5 dxc5 20.e5 Nh5
Here Stockfish 8 recommends 21.g4!? which is not the kind of move that I can see Bill choosing, as it seems to give even more exposure to his King. Yet the followup is ironic enough for him to appreciate: 21...Nf4 22.Qf3 Kg7 23.0-0-0 (made possible by the Knight's block of the Queen's diagonal) Ne2+ 24.Kb1 Nxc3 25.Qxc3 Be6 with an advantage to White after he captures the c-pawn.
21.Qc4+ Be6 22.Qxc5 Black resigned
Interesting. Compared to Stockfish 8's analysis above, the Knights are still on the board, which would slightly favor White's better piece. However, White's King is not castled, which could be quite risky. 22...Rhd8 would seem to guard well against White's possible Queen check at c7.
In a human vs human game, however, in the long run I would take the extra pawns over the extra piece. It would appear that Black agreed.