White retreats the rook having rejected moving his g pawn.

Opening up the White King. If now Kxg2 Bh3+ Kh1 Qg4 Rg1 Qf3+ Rg2 Qxg2 Mate.

So that rook scuttles off as well and White now has all his pieces bunched on the b, c and d file. The bishop is a particularly sorry sight with one square available. The king is isolated and vulnerable.

This sacrifice seems correct and looks to break through to the king before white can organise a defence.

Threatens Qf2 mate. Be1 or Nd1 fail to Qf1 mate. Nxe4 is probably the only way to avoid a quick mate. I saw Bh3 ( threatening Qf1+ Rxf1 Rxf1 Rxf1 gxf1= Q mate) which then seems to force Qd1. After that dxe4 threatens the f2 square again.

Forces mate by keeping White in check and so preventing any of his pieces assisting in defence.

White's King has been separated from his forces which are huddled on the Queen side unable to help.