Game Informer writes:
The story is paper-thin and often leaves you with no idea of what exactly is going on. I probably knew more about the plot going into the game than I did after the closing credits. There are also a few missions that involve stealth and platforming. While these are a welcome change of pace, they're rare, and the stealth gameplay in particular is underdeveloped.
A few other odds and ends also tarnish Viking. The undead warriors you fight seem to be mute, because they charge at you, die, and even call for help silently. This is a unique take on the undead, and I would have gone along with it if it was addressed in the game, but it wasn't so it just feels unfinished. The camera can also be an issue at times. In conjunction with the silent enemy factor, this results in some surprising moments where an enemy you didn't know was there jumps you from behind. Kind of sounds like a horror game, doesn't it? Maybe Viking missed its calling.
As it stands, Viking is a solid rental if you like bloody action games. If you enjoy the first few hours and can imagine replaying them six or seven times and still have fun, then it's probably worth a your money.