There are a large number of slots themed on the underwater life forms in the oceans and seas and one that immediately catches your eye is Great Blue from Playtech. Everything about this slot is about marine life, from the deep blue background with the bubbles to the cartoon-style symbols. The game has 5 slots and 25 fixed paylines. The coin size ranges between 0.01 and 0.25 and you can bet a maximum of 10 coins per line. The minimum wager in this slot is 25p and the maximum is £62.50.
Great Blue has a number of interesting symbols from the sea world including starfishes, sea horses, clown fish, turtles, and sharks along with the numbers 9 to Ace from a regular card deck. The wild symbol is the blue whale, while the starfish is the scatter symbol. The wild symbol substitutes all other symbols except the scatter and also doubles your win when it is part of a winning combination.
The bonus feature in Great Blue is the free spins bonus round. This round is triggered when you land 3, 4, or 5 scatter symbols across the reels during a spin. You get 8 free spins as a result. On the new screen that appears you get 5 oysters out of which you have to pick 2 to determine if you get additional free spins or a multiplier; you could get a maximum of 33 free spins if you clicked the right oysters and you could have a potential 15x multiplier. The free spins can also be re-triggered.
Another cool feature is the Gamble feature, which gets activated each time you win. This feature appears after each win, giving you a shot at doubling or even quadrupling your win. You could pick the correct color of the card shown to double your win or pick the correct suit to quadruple it. If you call correctly you can continue this feature till you reach the maximum limit. If you call wrong the feature ends and you lose your winnings from the spin.