20. Nxh4
'Battle of the Kings'
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20... g6
21. Nxg6
21... Bxg6
Interesting position, my friend. For the first time I wondered - what's next? lol
22. Nxd4
I wonder already the last 5 - 6 moves how the position developed. White had more rooks, that are in our analogy quite old people, and Black had more knights = youngsters. Despite this the position developed more in favor of White. Hm, either the analogy didn't work or there is a situation like in 21th century, with reliable old workers and work-shy lazy youth, lol
22... Nxd4
Interesting comparison. But I think Black is better. Yes, I have four pawns and they are all active, but the rooks in the center of the board really interfere with the whole performance 
23. Bxd4
23... Nb4
Lost track about the position, hope you are right
24. Nc3
I need cavalry lol
24... Nd3
No, no, you need more rooks, haha
25. Bcxd3
my center looks impenetrable 
25... Bxc3
Second question! should a pawn SOMEHOW reach the enemy promotion squares, does it promote a la traditional rules of chess.?
Yes, on the square on last (first) rank the promotion occurs in traditional way. On the square the pawn left on the 7th (2nd) rank, there appears a knight
19... Bxh4