Explain step by step -- e4: White opens the game by moving the pawn in front of their king two spaces forward.
c5: Black responds with the Sicilian Defense, moving their pawn in front of their queen two spaces forward to control the center of the board.
Nf3: White develops their knight, attacking the pawn in the center of the board.
d4: White pushes their pawn in the center forward to attack the black pawn.
Bb5+: White checks the black king by moving their bishop to b5.
Bd7: Black moves their bishop to d7 to block the check.
N1c3: White develops their knight, preparing to castle kingside.
Nd7: Black moves their knight to d7 to defend their king.
Nc7+: White checks the black king again, forcing it to move.
Kd8: Black moves their king to the center of the board, which is usually a safer place in the endgame.
Nxa8: White captures the black bishop with their knight.
Qa5: White attacks the black queen with their queen.
Nc7: Black moves their knight to c7 to attack the white queen.
Qb5: White attacks the black queen again, forcing it to move.
Be3: White develops their bishop and attacks the black queen one more time.
Qxb7: White captures the black pawn with their queen, gaining a material advantage.
Nxe4: Black captures the white knight with their bishop, removing the threat to their queen.
Nxf6+: White checks the black king with their knight, which cannot be captured due to the white queen's threat.
O-O: White castles kingside to bring their king to safety and connect their rooks.
Bxa7: White moves their bishop to a7, attacking the black knight and threatening a discovered attack.
f4: White pushes their pawn forward to create more space for their pieces and attack the black queen.
fxe4: White captures the black pawn with their pawn.
Bb6+: White checks the black king with their bishop, forcing it to move again.
Qxd5: White captures the black queen with their queen, gaining another material advantage.
Rxf5: White sacrifices their rook to open up the black king and prepare for a checkmate.
Qxe4: White captures the black pawn with their queen.
Rd1: White develops their rook, attacking the black queen and preparing for a discovered attack.
Re1: White moves their rook to e1, attacking the black queen again and pinning the black bishop to the king.
Kh1: Black moves their king to h1 to avoid the discovered attack and create a flight square.
Qb7+: White checks the black king with their queen, forcing it to move.
Rd5+: White checks the black king again with their rook, attacking the black queen and threatening a discovered attack.
Nxc7: White captures the black knight with their knight, gaining more material.
Rxf1: White promotes their pawn to a queen, setting up a checkmate threat.
Nb5: White develops their knight and attacks the black bishop.
Bc5+: White checks the black king with their bishop, forcing it to move and preparing for another discovered attack.
Nxc7#: White delivers a checkmate by capturing the black king with their knight.
Thus, the game ends