It has a Nordic mythology because the symbols include Jarl (the son of God Ríg), Valkyrie (choose death and the people who live in battle), Fenrir (the ferocious wolf), Raven and Longship.
One more thing, Ice Wilds wins with a 5x multiplier, which means feature bets are enabled. Hammer Wild can also replace any symbol and use a 3x multiplier to win - it falls on reel 2 and removes any Ice Wilds frozen on the reel.