I was very impressed by the battle rules, both as a set of wargames rules and as an evocation of the period. The campaign rules are apparently even more impressive.
The pre-battle praying, fighting and boasting really helped add to the flavour, and I would think only really work within the dark ages setting. Most of the rules it would seem though could happily be warped into a more standard fantasy setup, which I'm definitely keen to try out for my Newhammer project (although it definitely falls down on my 4th rule for that, more on that later).
Some of the systems, such as the activation process and the random element to movement are probably old hat to people who haven't been out of the wargaming loop quite as long as me, but I quite enjoyed working within the constraints they imposed. The lesser control than I'm used to also seemed to add a slightly more relaxed air to the proceedings (although that might be down to a good opponent and GM). The system for shock (impacting both morale and fighting power) also seemed both a good idea and well implemented.
The real heart of the game though is the Fate card system, whereby throughout the game you can buy random cards, which may be more or less useful for a particular side (or even in some cases completely useless) and can then be spent to boost a unit during its turn, or help counter an opponent's move. They give a nice hidden element to the contest, vaguely reminiscent of the role of magic in Warhammer, and also I felt added a hint of the mythic over the mundane. However they also impose a real limitation on the flexibility of the game (or conversely creates the ability to produce supplements) in that each new army needs their own card set. While I'm sure you could invent your own, in much the same way as you could invent your own codex for modern WH40K, this would always be unsatisfactory and subject to debate.
So while I would heartily recommend the game for some dark ages skirmishing, I'm also disappointed that it's inherently limited in what it does. Although I do have some plans for some dabbling...