Hammerstorm

Hammerstorm is a Norse-mythology slot from Pragmatic Play on a classic reel set with many paylines. It has no standard Free Spins round. The main bonus is a Respin feature that starts when a Thor symbol lands alongside lightning symbols, with more lightning landing during the feature to extend the respins.

Coloured gems, red, green and purple, unlock chests that switch on modifiers. Double creates gold-coin versions of ordinary symbols that are worth more. Expand enlarges the collection zone from a small area up to a large square. Spins adds extra respin symbols to the reels. They can all be active together, and a wide collection zone sweeping over many gold coins is where the feature gets its force.

It may suit players who like modifier-driven bonuses where each trigger plays out differently. The free demo uses play credits, not real money, and every spin is random.