The following game appears to end too soon. The position is equal, which should not bring on feelings of loss - unless the defender was troubled at having moved from a "won" game at move 4 to an even one, and decided to let the game go.
The answer, as with many 1 0 bullet games, probably lies with the clock, as we shall see.
angelcamina - plutonia
1 0 bullet, lichess.org
1.e4 e5 2.Nf3 Nc6 3.Bc4 Bc5 4.Bxf7+
4...Kxf7 5.Nxe5+ Nxe5 6.Qh5+ Kf8
7.Qxe5 Qe7 8.Qf4+ Nf6
9.d3 d5 10.e5 Kg8 11.O-O Nd7 12.d4 Bb6 13.Nc3 h6 14.Nxd5 Black resigned
White has 3 pawns for his sacrificed piece. Black's King has found relative shelter. Balance. Why the resignation?
My guess is that Black realized that he had only 17 seconds left on his clock, while White had 39 seconds. Black would have to make "ordinary" moves in a rather ordinary position, twice as fast as White, to have a chance to win the game. That probably wasn't an attractive option.