The Great Blue of the title is of course the whale and it certainly lives up to its name by delivering some potentially massive jackpots. The whale acts as the Wild symbol and substitutes for all other symbols apart from the scatter. Any winning payline in which the whale appears will be doubled. If you're lucky enough to find a 5 symbol combination an enormous 10,000 coin win will be yours. The wilds can also become stacked to fill up an entire reel, offering more opportunities to hit a winning combination.
Great Blue comes with a Bonus feature which is triggered when 3 or more sea shells appear anywhere on the reels. You'll receive 8 free spins with a 2x multiplier to start with but there are chances to really improve on this initial offering.
Once activated, you'll be presented with 5 sea shells each hiding a multiplier or extra spins - you get to choose 2. If you manage to pick the maximum of 33 spins or the 15x multiplier, the wins can really mount up. Look out for the scatters during the Bonus feature as more free spins can be triggered indefinitely.
Graphically, there are more sophisticated slots on offer than Great Blue. The reels feature a selection of aquatic creatures including starfish, seahorses and sharks, all set against a pale blue oceanic backdrop. Likewise the soundtrack, which is fairly basic too.
What it may lack in stunning looks, Great Blue makes up in the features which are the key to swimming away with buckets full of coins. High rolling gamblers are known as whales and Great Blue is best navigated by players with a bankroll that can cope with the high variance.
Despite the watery theme, you'll go through plenty of dry spells. When you do hit the free spins and manage to find a big multiplier, the results can be extremely lucrative. If you like sea-themed slots, Lord of the Ocean by Novomatic matches up in terms of volatility as does Nemo’s Voyage by WMS.