Its more active, but can suffer later from a pawn menace.

After 21....Bxc4 22.Bxc4 bxc4 Black's central pawn majority once again takes -erm - centre stage, whilst White's Q-side majority is relegated to the - uh - wings... I can never resist this sort of thing...  

22...Nb6

If 22.Ba4 Nb6 23.Bb5 with the view of supporting the bishop by a2-a4 at some point. But it is a hard decision all the same to take the bishop in that direction, where it might have become cut off from the rest of the army.

True enough. That bishop capture on d4 has turned out very well.

Interesting remark! Was Black really aiming to take on c2? Check out this line: 24.Bh6!? Nxa2!! 25.Nxa2 Rxa2 26.Bxf8 Kxf8 27.Rb1 Qb6+. For the exchange, Black gets 2 pawns an a phalanx of pawns that will charge right through White's game. Maybe White saw this coming.

The text may be safer due to b3 attacking the defender later after the rook escapes the attack.

Either capture was good. It's not easy to pass up the opportunity to establish a passed pawn on the 6th rank. On the other hand, a knight firmly established deep in the enemy position is not to be sneezed at neither. One of those tough decisions that tells you you have a really good game going.

Possible was 28...Bb3 29.Rd2 Rfd8. See how this rook move indirectly protects the d-pawn. If 30.Bxe5, dxe5 discovers Black's major pieces direct protection, and Black's other centre pawns are ready to roll. White is just hanging on here (though I reckon on the whole his defence has been pretty good so far - he's still in the game).

Good catch!

So nearly possible for white (31.Nf6+ exf6 32.Qxf6) with Bh6 intended, but (32...Nxf3+! 33.gxf3 Qg4+ 34.Bg3) and the threat to black is over, and (33.Kf2 Nh5) fails.

White's first real mistake (give or take his 22nd move, after which White found himself thrown back onto the defensive). Though in difficulties, White could not have been said to have been losing before this move. A better attacking chance lay in 31.Ng5, although it is true that Black's resources would have been sufficient to hold out the attack and continue his own at the same time. Probably White ought simply have played 31.Re1 and waited for a more opportune moment to lunge for the Black King.

33.Ng5 with Ne6 intended would have to be better.

No. 33.Ng5 Rxc1 finishes White off. White's best - and a sorry best it is, now - 33.Nc3. White was lost whatever he did.