Double Bubble Slot Machine

Video slots with underwater themes have been around since the days of the Megalodon, the prehistoric shark that inspired Deep Blue Sea. OK, I’m exaggerating a little, but we’ve certainly seen plenty of underwater-themed slots flood the market, if you’ll pardon the pun. From Underwater Pearls and Deep Blue to Triton’s Treasure and Under the Sea, slot developers can’t help diving into the ocean and coming up clutching yet another new slot game. Double Bubble, from Realistic Games, is one such title.

Double Bubble first appeared in 2014. The five-reel slot boasts 20 fixed pay-lines, on which users are tasked with building winning combinations from left to right. It gets better, though. As you explore the murky depths, you’ll look to play the Free Spins bonus game, which entitles you to ten complementary spins. Double Bubble is available on PC, iPhone, iPad and is a perfect slot for Android devices.

Deep-Sea Diving

There’s plenty of coral on display in Double Bubble. Lurid crusts in various colours – pink, green, orange, red, purple, blue – fight for the viewer’s attention, appearing behind the reels. The 5x3 grid sits within a purple border, beyond which lies the traditional control panel, home to all the usual buttons. The control panel has been designed to mimic a physical machine inside a bricks-and-mortar gaming house. The panel contains a button which triggers the AutoPlay function, as well as up and down arrows to regulate your total bet. If you wish to use AutoPlay, be aware that you can set the game to spin 10, 25, 50, 100 or even 500 times without the need for you to do, well, anything at all. You can also switch on the fast reel spin option, a function usually appreciated by impatient and/or experienced gamers.

To get started, you’ll need to stake a minimum of one coin for each of the 20 pay-lines. The minimum slot coin denomination is 0.1, while the maximum is 1. The jackpot, meanwhile, is a rather tasty 10,000x your stake-per-line.

The house edge of Double Bubble is 4.93%, although it’s worth double-checking with the casino leasing the game.

Creatures from the Deep

Don’t expect an extended cast of characters in this body of water. There are only three main character symbols in total – a dark blue seahorse, a red pufferfish and a yellow-and-purple tropical fish. In addition, there is a worn gold coin bearing the image of a parrot, and a snarling shark icon.

The shark is the game’s wild. Accordingly, it can replace the game’s other symbols to help you build matching combinations. The shark cannot, however, stand in for the coin.

You’d do well to avoid sharks in real life, but in Double Bubble, you want to find as many of those sharp-toothed predators as possible. After all, five sharks in a line pays the game’s jackpot, a cool 10,000x your stake-per-line.

The other character symbols are not nearly as enticing, but some handsome wins can still be achieved. You’ll bag 800 for five purple fish, 600 for five reds and 400 for five blues. Five aces, meanwhile, pays 200. The pay-outs for slot machines fall rather steeply when you land less than five matching icons.

Care for Some Free Spins?

There is only one bonus feature in Double Bubble, and it’s the usual free spins free-for-all. This is activated when you land three or more golden scatter coins anywhere on the reels. Unlike the other icons, the golden coins do not need to form from left-to-right. If you find three, four or five, you’ll be entitled to ten free spins. During the bonus, finding the Double Bubble logo icon, which pops up on reel three, will furnish you to a 2x multiplier on your running total. Neat!

As well as supplying free spins, the gold coins are linked to multipliers in the pay-table. Three coins grants you 1x, four pays 10x and five comes with a staggering 125x your total bet.

Unfortunately, free spins cannot be re-triggered during an active free spins bonus round.

Worth Getting Wet For?

Double Bubble might not be laden with bonus features, but it’s nonetheless a pretty decent game. We like the balance-doubling feature during free spins, the fact that scatters are linked to multiplier symbols in slot games, and the fact that the wild is an angry-looking shark. On the downside, the playing card icons are boring to look at (every one is identical, from 10 through to Ace) and the pay-table lacks the wow factor.