..e5 was certainly playable here, with a less cramped position than in the game. Computer analysis would be helpful, but my guess is the eval would be nearly equal.

< 10. ..Nd5 >

Yes <Ulhumbrus> ..Nd7 was a viable alternative here. Black could have combined this with a few other tempo saving moves. For example... 10. ..Nd7 11. Qe2 b6 12. c3 Bb7 13. h4 Rfd8 14. Nf1 Nf8 15. h5 Rd7 16. Bf4 Rad8

< 12. ..a5?! >

Obviously played to develop Bc8-a6 with gain of tempo by attack on the Q, but this is too slow, and the a6-f1 diagonal proves useless.

< 13. ..b5? >

A positional and tactical blunder, as well as loss of tempo. If b5 is advantageous, it would have been quicker to play b7-b5 directly. But now with the knight on d5 it allows the very nice...

< 14.a4! >

A well timed and played move!
If now ...b4 15. c4 Nb6 16. b3 Bb7 17. Qg4 Nd7 18.Bb2 and white has the space advantage, is beautifully poised for K-side attack, while black's Q-side expansion is shut down. White has the clear advantage.

< 16. ..Rab8 >

On 16. ..Bb5 white must either retreat the rook or try 17. c4 Bxa4 18. cxd5 exd5 19. Qxa4 Nb4 20. Bf1 and it appears black has poured cold water on white's forward motion.

< 23.Bg6! >

Annihilation of defense.

With < 25. ...Kf8 > black was prepared to return the knight in order to find a flight path for the K via e8-d7-c8. Qxg7+ would still result in a win as white is up 2 pawns. But instead of Qxg7+, the simple Ne4 opens the diagonal for Bc1-h6 and black has no defense. If 26. ..Nxe5 Qxg7+ and Nxe5 and black gets nailed to the wall (the 8th rank).

The final position is astounding. All white's peices are coordinated in the fight, and the black position is a complete disaster. If either K or Ng7 move its immediate mate. The Be7 has no squares and can not move without being lost for nothing. The LSB has nothing to do. The Q is disconnected from the kingside and offers no defense. The rooks are connected but have no way to contribute to either attack or defense. The only available rook ideas fail miserably..

If 26. ..Rd7 27. Bh6 Bd8 28. Nd6 (threatening Qe8++) Rxd6 29. exd6 Qd7 30. Bxg7+ Kg8 31. Be5+

and 26. ..Rd3 is a waste of time 27.Bh6 Rxf3 28.Bxg7+ Kg8 29.Bf6+