Play Booster for Free

The game's 25 paylines are fixed, with stakes offered from 0.01 to 1.00 – meaning your bet ranges from 0.25 to 25.00. These stakes probably won't attract the high rollers. Mind you, with the low volatility in mind, this game is aimed firmly at a more casual or recreational gambler.

How much you can expect to get back on your bet is determined by the RTP. Booster’s RTP is impressive at 97.04%, which should give you a good return over time.

A star-filled screen opens up as players are propelled through space at warp speed. The 5x3 reels are see-through and filled with familiar retro slots symbols of bars, stars and 7s. In fact, Booster was slated to be called Mystery 7s before a last-minute name change was issued by the development team.

There are only six symbols on this slot. These often appear stacked and they give this low-tech game its clean, simple lines. Reel spins are accompanied by a percussive, space-age tune. iSoftbet do love their ambient soundtracks, and Booster offers the perfect setting for one.

Payouts at the upper end of the pay table offer some serious prize potential. The blue 7 pays 200 coins for five of a kind. The red 7 boosts up the prizes to 500 coins for a full matching five. The base game's top jackpot, however, comes from five glittering purple diamonds that will award 2000 coins to the lucky winner.

There's a refreshingly high-frequency hit rate on wins for this low volatility game. There are no wild symbols or scatters, and no further features during base game.

However, there are plenty of thrills when it comes to the game's bonus feature.

Land between three and five of the lightning flash bonus symbols and this simple, fun game will be propelled into a different dimension. The backdrop turns a deep red and the soundtrack kicks up the gears as the bonus screen comes into play.

The screen fills up with a nine-square grid, offering eight different bonus options. Hit the central start button to see the squares light up sequentially. Where will they stop? What bonus option will you hit?

The possibilities are as follows: 5 free spins with 5x multiplier, 10 free spins with 2x multiplier, 10 free spins with 3x multiplier, 15 free spins, 50 free spins with 2x multiplier, 100 free spins or 6000 coins. The Mystery Box option will include any one of these bonuses.

Players can't retrigger during free spins, but bonus symbols now pay out as scatters. Impressively, three of a kind will pay 30x your total bet. So, with all these options, you can see that there are some really big wins possible from this real cash-boosting bonus round.

iSoftbet's platform means gorgeous high-definition graphics and slick gameplay on all formats, from desktop to smartphone. What’s more, the mobile-optimized game has functions that really suit the touchscreen.

The simple gameplay and appealing soundtrack make this an easy game to play either for a few quick spins, or for some longer downtime. With its RTP and pay table this promising, the Booster video slot is a super option to play for real money.

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As space is the final frontier, there are galaxies of space-themed slots available to play online.

Games that offer a very similar space-age experience for players include Netent's classic Starburst or iSoftbet's Wisps – both of which feature a simple structure with an ambient atmosphere. These are solid games with appealing graphics that fit into the same category as Booster.

If you want a more immersive space experience, you should check out Endorphina's intergalactic mission 2027 ISS. Equally, for a brilliant retro ride, Play'n GO's Space Race is unbeatable.

However, for players who love the thrill of the bonus round, then Novomatic's Red Hot Repeater does a superb job of building anticipation and potentially hitting big. It's another simple, classic base game with all its clout in the bonus action.

Fans of software by iSoftbet will be on familiar ground with the Booster video slot. Atmosphere and mechanics echo other successful online slots they've produced. So if you're looking for innovation and ground breaking new features, then Booster is not your game.

If, however, you like high-quality, appealing 3D graphics with low-tech, easy-to-play mechanics, then you're in for a treat. The free Booster slot does what the iSoftbet team know how to do so well.

It's a gorgeous game with excellent playability that makes a pleasant experience. There's loads of action in the base game's high hit rate. Plus, there are some real thrills from the bonus feature. What's not to like about all of that?

A great game for mobile and a big hit to play for real money, Booster is definitely a strong addition to the iSoftbet canon.