I think one thing about IN that makes them so annoying for some people is the fact that black metal box seems to be too narrow for them and they feel free to play what they like and not what is supposed to be played by black metal band. Heavily influenced by crust punk and grindcore, they created their very own and original, although sometimes chaotic sound.
Third album of the band is their most diversified work, while keeping insane brutal blasting tracks (2,4,7,9) they step towards more melodical song writing (3,5,11) and slower, even doom tempos (6), some space left for crustpunk black (8,10), intro/outro can`t be missed, all squeezed in half an hour. Songs just differ one from the other, highlits for me are Blood Is Thicker than Water and Total War - Winter War. One more thing - bass play is excellent throughout all album and has one exceptional, steely sound.