Saves the e-pawn. Perhaps f3 could've been considered as well as as not to let the black knight to the center?

Knights looking good, but once the black knight moves there is a revealed threat in e4, so care need be taken.

saves the white knight, and reduces the fork after Ne2+, but loses the open c-file to black and helps black develop the quiet f8 rook. Better - Ng3.

?! Looks good but a milder Ng3 could've been better to protect e2.

?? Doesn't spot the thread Nxd4. After that trouble starts.

The only way not to lose the a4 pawn, but the white officers are awkwardly placed and the black knight is very powerful where it is.

Rxb2 Rc1+ Bd1 Rxd1 checkmate

and the game is done with the coronation of the b-pawn.

Qc1 would've pinned and then killed the bishop but that would've been tacky. I tried an equally effective but less crude end.

Frees the e2 square for the knight, trying to go for a beautiful mate, but misses one escape route.