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It's really not. If anything it's easier and more intuitive than (say) the Song of XXXX stuff from Ganesha, which is about the same "scope" of game in terms of figs and play time. You're making one dice roll (usually 2-3 dice) compared to a static number to determine whether you hit, and the same roll determines damage. Relatively few models have multiple attacks, and gameplay is quick and bloody. I can't speak for game balance or campaign play in 2nd ed, but 1st was always a smooth-playing game and easy to pick up and teach. Biggest handicap was the general lack of support from ICE after release and a rather ugly line of dedicated miniatures.
Not familiar with the 2nd ed changes or the scenario you were playing, but zombies are dirt slow. Maybe better to avoid them as much as possible and go do whatever "discovery" objectives the game calls for while your toughest characters stall the bulk of the baddies? Assuming decent armor, defense, and endurance, a single Dwarf warrior type ought to be able to stand there tanking four or more zombies for quite a while. d6+d10-1 for Low damage is fairly wretched offense.
The more normal races were better supported, but because there were so many factions even the main human "nations" generally only had a pack or two of figs.
I read through the free rules a while back. What do those who have played it see as its main attraction? The combined damage/to-hit roll seems quite elegant, with a very wide range of potential damage, but I don't recall anything that seemed particularly striking in the way that SoBH's risk/reward system and Fistful of Lead's card-based activation are. It was a while ago, though ...
As I said earlier the idea of a magical "weather" effect ("It's raining swords...") restricting fights to at most large skirmish scale was an appealing idea.