Rubbish! A true waste of 90 minutes... and of Mads Mikkelsen!
It evidently attempts similar as to what we would later see in 2022 with (the excellent) 'The Northman', though simply falls flat in every department for me. The whole production just looks so cheap and low-budget (which it wasn't), without even noting the (admittedly intended) pure misery of the look of it all too. Editing, notably with the needless chapter breaks, is also a negative.
As mentioned already, a mute Mikkelsen is completedly wasted... may as well have cast Joe Bloggs. The rest of the cast have very little to work with either, though minutely interesting to see Gary Lewis and Jamie Sives involved. I wouldn't say anyone onscreen deteriorates the film (it does so itself), but they also don't do anything to improve it either.
I was anticipating 'Valhalla Rising' to be an entertaining one. It wasn't. Thankfully they had the awareness (or were restricted?) in keeping it 'short' at 90 minutes... a dreary 90mins, albeit.