"Fantastic" is selling the game here a bit high, but the good thing about the Alekhine is that it's fairly uncommon as 1. e4 defenses go and tends to imbalance the game rather quickly, making it a good choice for dogged and creative hypermodern players.

The Alekhine is my principle answer to 1.e4. I've been playing it since the mid-70's and I agree that it's a fantastic defense  

The 5.Bf4/6.Nd2/7.dxe5 sequence loses the game for white, from a positional viewpoint. Black's plan in the Alekhine is primarily to attack white's pawn center, and secondarily to scare up Q-side counterplay. This move sequence by white plays right into black's plan. White should play either 5.exd6 (eliminating his over-extended e-pawn), or 5.f4 (attempting to maintain the pawn center).

That's happened to me many times playing the Alekhine as black against lower-ranked players. Niggle the center with pressure, watch it overextend and collapse with little prodding really. The problem is that the most testing white variations are much harder for black to defend than the most testing white variations of other black-to-play openings. White didn't play correctly in the opening. 5. Bf4 is bad. He should have gone into the Exchange Variation with 5. exd6. The standard modern variation with 4. Nf3 (instead of 4. c4) is good.

sure You are absolutely right! And many thanks for your comments. But... you know - the winner in the chess is who makes the before last mistake  

To meet 17. a5 with 17. ...Nxc4. White can resign here. Harsh but true.

It takes a special kind of pawn-grabbing greed to "win" your opponent's rook-pawn that makes a bypass to your castled king position (Even if black didn't have 20. ...g6 this would have still been disastrous).

Mind you, 23. ...Qh5 24. h4 Nxh4 is a simpler and arguably quicker route to victory.

but you'll agree 23. ... Rxh2 is more beautiful and unexpected