100% Swiss 
Thor's Lightning - Online Slot Machine
Summon Thor's Lightning and Hammer to smash the central locked tiles with Winning Clusters and enter Valhalla or Muspell's Free Spins in this 7x7 high hit-rate Nordic adventure!
A cluster forms when symbols of the same type land vertically or horizontally adjacent to one another. All clusters of five or more identical symbols award a win!
Land 40 of the top paying hammer and you’ll receive a payout of 25 times your stake. There’s also a wild which replaces all paying symbols. Red Tiger Gaming has packed in a good selection of extras here:
Lightning Strikes feature - on any spin, the animated Thor can summon up a lightning strike. This can remove lower value symbols from the reels or turn a random selection of symbols into the same one (or better still a wild).
Hammer Strike feature - Thor can throw his hammer onto the reels on any spin. This could lead to a nudge or symbol removal which leads to a new winning combination being created.
In the centre of the reels you’ll see a 9-symbol free spins block. These symbols are locked. Land a winner adjacent to a symbol and it unlocks. Unlock all the blocks in the same set of symbol drop sequences and you’ll trigger Valhalla or Muspell Free Spins.
