First off, Ensiferum have a special significance to me. This band, indeed this album, was effectively my introduction to metal. It was the songs Hero In A Dream and Token Of Time that sold me on the genre.
Moving on... Ensiferum, like Finntroll, Turisas and others, play something that is probably best described as 'Viking metal'; unlike the others, though, Ensiferum evoke the medieval atmosphere through their melodies rather than heavy use of traditional/folk instruments. That was the thing that struck me when I first heard this album: though it is very much metal, played with bass, drums, electric guitar and growling vocals, it still manages to sound medieval.
Simply put, Ensiferum are, in my opinion, the best medieval metal band out there, and this is their best album.