This simply is not a very fun battle to play much less replay several times. It lacks true tactical choices, and in the end feels more like an Xbox console game boss fight where the designer just throws more zombies at the player rather than a serious wargame.
There are plenty of tactical choices, you probably just aren't familiar enough with the game to take them. The scenario is hard, it was meant to be hard, but with the right tactics it can be regularily beaten. You can't skip scenarios, because of the core units you must carry and improve through the campaign. If you could skip, players might jump ahead to campaign scenario 6, get their butt kicked because it is unbalanced, and then complain that this isn't a serious war game.
Very serious, there isn't a joke in the game, but I think I'll add a couple of one-liners in the next iteration.
World at War: Revelation, a creepy, military action, alternate history, World War Three novel. At Amazon Kindle Direct Publishing (http://tinyurl.com/mcgcht8). Only $3.99. What the hell?