The walkthrough for Viking: Battle for Asgard is split up into three main sections, as defined by the game's division of playable land into three large islands: Niflberg, Galcliff, and Isaholm.
Each island strategy is split up by objectives: details on when they can be reached, the best order to complete them, how to complete them, where to go for them, and what happens after completing them.
If you don't understand what an objective is, please see Getting Started/Objectives.
The game begins with a small history of events, and a narration of the struggles of the vikings against Hel's forces in an artistic, illustrated animation. After fading to black, the game loads into a cutscene depicting the last settlement on the island of Niflberg, Brighthelm, being raided and set afire by Hel's Legion. Skarin lies in the grass, dying, until Freya comes to his aid. In a flash of light, Hel's Legion is pushed back, Brighthelm is repaired back to normal, and Skarin is brought back to full health.
After looking around at the scenery, the game moves the camera behind Skarin and gives the player control.