Well, what were the alternatives?

Not attacking Poland, of course. Well, then the Drittes Reich would have been bankrupt (not too bad allternative).

The invasion of Scandinavia and France went pretty well. Dunkerque could have been better, though.
I think Hitler had a little chance then to end the war. We all know that Churchill's Britain was not willing to give in, but I always wondered what would have happaned if Germany offered peace at relatively good terms to France and Poland. Taking Elsac-Lorraine and Danzig to the Reich, but leaving the rest. Making a military political and economic alliance with Poland, the BeNeLux, Norway, Sweden and France. Germany would have been the leading nation on the continent. What reason would Britain have had to go on fighting? What reasion the USA to join the war. Hitler could have waited some years and then invading Russia.

The other chance was the submarine war. With a focus on this weapon and w/o that Enigma stuff, Germany would have a chance to cut off the British Islannds and to force Britain to peace. Maybe not a lasting one, but at least a chance.

I do not believe in anything else. Why should Germany have won the war, if it was able to take seize Suez? It would have been some trouble for Britain to loose the swa route throught th Med, but Germany would not have had the resources to invade Arabia or even India.
Moscow? Even the fall of Moscow would not have ended the war against the Soviets.