Thor appears and summons lightning. It may remove all low-paying symbols or transform random symbols into new matching ones—or wilds.

Thor hurls his hammer across the reels. It can either remove random 2x2 symbols and replace them with high-paying ones or nudge random rows or reels to guarantee a win..

Nine inactive tiles sit at the centre of the slot. Winning clusters that land next to them will unlock them. Break all eight outer tiles in one chain reaction to unlock either Valhalla Free Spins or Muspell Free Spins.

Thor removes all the tiles, and golden shields take their place for the duration of the round. Any golden shield that lands will lock in place until free spins end. Each shield reveals a random stake multiplier at the end of the round.

Thor clears all low-paying symbols from the reels. Only high-paying symbols drop in for the rest of the round. Only two bonus features can trigger here: Lava Flow and Lava Shower.

Lava showers fall randomly during Muspell Spins, destroying one or more types of symbols and awarding a free respin.

Lava flows across connected reels, filling them with matching symbols.

A winning cluster forms when five or more matching symbols land adjacent to one another, either vertically or horizontally.