Thunder Gems Slot - Review, Free & Demo Play logo

Thunder Gems Slot - Review, Free & Demo Play


What about scattering some colorful gems and gaining valuable wins? Everything is in your hands with Thunder Gems, one of the newest slot machines, released on 27/03/2023 by Octavian Gaming. In this review, you will get a unique opportunity to get a first look at the interface and design of this slot machine, know more about its layout, mechanics, symbols on the reels, and, of course, valuable bonus features. Let’s dig deeper for the treasure stones together, shall we?

Software: Octavian Gaming
Release Date: 27.03.2023
Volatility: Medium
RTP: 94.0%
Multiplier: Yes
Max. win: 100x
Bonus game: No
Free spins: Yes
Scatter Symbol: Yes
Wild symbol: Yes
Symbol Stacked: Yes
Jackpot Game: No
Slot lines: 243
Slot reels: 5
Layout: 5-3
Stakes range (€/£/$): 0.20 to 20
Slot Theme: Gems
Technology: JS, HTML5

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Thunder Gems Free Play

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How to play

To start playing Thunder Gems either for real money or in a free demo mode you have to:

  • Open the slot in your desktop or mobile browser
  • Click on the Settings Menu icon on the left side of the screen and see the available bonuses and symbols
  • Adjust the game sounds by pressing the sound button in the lower-left corner
  • Select your bet value between €0.2 and €20
  • Click on the circular arrow button to start the first round
  • Wait for your wins

Thunder Gems is a virtual slot machine with a 5x3 layout and an impressive number of 243 pay ways in total. In order to gain real cash wins, you have to land combinations of identical symbols on active paylines from leftmost to rightmost. All values on the paytable are dependent upon your selected bet value, meaning that if you bet more, you also have higher chances of getting more valuable rewards.

Before starting your game, make sure that you have studied the slot’s paytable thoroughly and know about all the present symbols and their payouts, as well as the bonus features that can multiply your rewards. The total win from each round is multiplied by your selected bet value.

Thunder Gems RTP and Volatility

Thunder Gems has got an RTP rate of 94% and medium volatility.
While Thunder Gems is quite a generous slot machine in terms of symbols and bonuses, its RTP rate could’ve been much better. Given that the accepted medium in the industry is set at 96%, the RTP of this slot is 2% lower. It doesn’t necessarily make it a fruitless game with too many dead spins, but you may struggle to get big rewards at first anyway.



Thunder Gems

While Thunder Gems is not an elaborate slot machine in terms of its concept or a general idea, it's still intriguing both for experienced gamblers and newbies. If you enjoy simple slot machines with detailed and colorful symbols and don’t want to immerse in any kind of plot, Thunder Gems is designed just for you. At the same time, if you’re a first-time player and looking for a slot with easy and comprehensible mechanics, Thunder Gems is the best pick.

Given that Thunder Gems is revolving around valuable gemstones, its regular paytable consists of colorful gem symbols: sapphires, emeralds, rubies, amethysts, and ambers. Apart from them, you can find 3 different Seven symbols: a single Seven and a combination of 2 and 3 numbers, their values rising respectively. Finally, the most valuable symbol on the slot’s basic paytable is BAR, capable of giving out up to 100x your total bet.

The special paytable in Thunder Gems consists of Free Spins and Wild symbols. Wilds substitute for all basic symbols on the reels, increasing your chances of creating more winning combos, and Free Spins symbols give out different bet multipliers and activate Free Spins.

Thunder Gems slot - payouts

Mobile Compatibility

Thunder Gems slot mobile
Thunder Gems is one of the newest slot machines on the market and its made with the use of HTML5 and Javascript technologies. Thanks to HTML5, you can enjoy this game in your desktop browser without downloading and installing any additional software to play. At the same time, this makes Thunder Gems a perfect online slot to play on mobile devices. There is no need to download any application for this: you can just launch the slot machine in your Android or iOS mobile browser and enjoy your spins whenever you have a stable Internet connection.

About Octavian Gaming

Octavian Gaming is an experienced slot provider that was founded in 2008 and is based in Italy. Even though the company is not as popular as some leading casino providers in Europe, its current portfolio is made up of over 100 high-quality titles. Octavian Gaming are masters at both classic and thematic online slot machines, providing gamblers with unique plotlines and memorable characters in almost every game. Some of the latest releases by the company include Fireballs, Scary Clown, God of Olympus, Fruits & Stars, and, of course, Thunder Gems, which we are reviewing today.

Bonus Rounds & Free Spins


Free Spins

Free Spins in Thunder Gems are activated by Free Spins symbols: 3, 4, or 5 symbols pay 3x, 5x, and 10x your bet respectively and trigger the bonus round. In the beginning, you have to select 1 symbol to define the number of spins. During the Free Spins round, the accumulation bar on the top of the screen is locked, and a random multiplier between 1x and 50x is selected on each spin. Notice that if you activate Free Spins while the Advanced Mode is active, its rules persist.
Thunder Gems slot - feature

Accumulation Feature

Do you see a bright purple bar on top of the reels? This is the so-called accumulation bar, and your every win during the base game fills 1 position on the bar. Gaining 3 winning combos in a row is enough to fill up the bar and activate the Advanced Mode.

Advanced Mode

The Advanced Mode in Thunder Gems is activated once you fill-up the accumulation bar above the game board. During this bonus round, all Wilds on the reels might be stacked in combos of 2 or 3 symbols, and a Cascade Feature is available.

Cascade Feature

The Cascade Feature in Thunder Gems is available during the Advanced Mode only. All symbols that do not participate in winning combos explode on the reels and disappear, creating room for more symbols to fall on the empty reel positions and increasing your chances of getting more rewarding combinations. At the same time, symbols that are part of winning combos, as well as Wilds and Free Spins symbols will remain in their positions.

Thunder Gems Demo Play

In order to give Thunder Gems a try you don’t have to sign up with a casino and make a real cash deposit right away. Instead, you can try out all the features and bonuses of this slot machine in our free demo version. Just launch the demo from this page any time you want and enjoy Thunder Gems for fun without registering or downloading any special software. You are also not required to place a bet in real money in this demo mode.

Max Win

The max win you can achieve in Thunder Gems is 100x your wager.
The top win according to the paytable in Thunder Gems is 100x your total bet. You can get this stake multiplier by landing a winning combo of 5 BAR symbols on one of the active pay lines. Notice that winning such a prize is only possible if you select the maximum bet value before making a spin. Your stake can be also multiplied by the variety of bonus features this slot offers: Free Spins, Accumulation Feature, Advanced Mode, and a Cascade Feature.

Thunder Gems video review

Thunder Gems (Octavian Gaming) 💥 Slot Review \u0026 Demo 💎 ✅ Try this slot for free on our website -\n\nHi everyone! In this video we’ll show you bonus game in Book of Vampires from Octavian Gaming. The slot machine has average volatility and RTP of 94.0%. The playing field consists of 5 reels and 3 rows, the minimum bet starts with $0.20, and the maximum bet reaches $20. By the way, the maximum winnings are 100x of the bet size.The main features of the machine are Free spins, Scatter Symbol, Wild symbol, Symbol Stacked.\n\nWrite in the comments, have you played Thunder Gems from Octavian Gaming and how do you like the winnings presented in this video!\n\nNo links used during live stream or in the description are transaction links.\n18+ | Play Responsibly |\n\n#slots #onlinecasino #bigwin
Overall Rating
Thunder Gems is an entertaining slot machine with a classic 5x3 layout. It is a relatively new slot machine, so it has an impeccable graphical quality that remains on top regardless of the device you play on. Even though Thunder Gems doesn’t have an elaborate concept, the game is still packed up with some tempting bonus features that are likely to boost your luck. Make sure to play Thunder Gems in a reliable online casino or try out our free demo version as soon as you have the chance.
Free Spins
Accumulation feature
Bet multipliers
Cascade Feature
No progressive jackpot

Thunder Gems Slot - FAQ

Do I Need to Make a Deposit to Play this Game?

Yes, but only if you intend to play Thunder Gems in a casino for real cash wins.

What is the Most Valuable Symbol in Thunder Gems?
The most valuable symbol you can find in Thunder Gems is the Wild symbol, which substitutes for all regular symbols on the game board.
What is the Return to Player (RTP) rate of Thunder Gems?
Thunder Gems has got a rather low RTP of 94% and medium volatility.
Can I Earn Real Cash Prizes in Thunder Gems?
Yes, but you have to register in a reliable casino and deposit some funds for your bet first.
Does Thunder Gems have a progressive jackpot?

No, Thunder Gems is a non-progressive slot machine.

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Joe Booth

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Joe is an expert online casino player, who knows all the tricks and tips on how to get to the most massive wins. He is also an experienced online casino games reviewer, with hundreds of written articles behind him, on all kinds of online casino games. He makes sure to play them, see how they work, and then gives his honest expert opinion about them to other players, our readers. 

Reviewed by Editor-in-Chief:
Aleksandra Andrishak
Updated: 01.08.2023

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