Thunder Diamonds 2: Hold and Win Demo & Slot Review

Thunder Diamonds 2: Hold and Win Review

Sequels, continuations, remakes, you name it. Today's media relies heavily on familiar ideas, and the iGaming market makes that more than obvious. Mentioning the Bass series, endless Zeus shenanigans, and one particular raccoon would be redundant at this point. However, I personally enjoy seeing good ideas grow into full-fledged series, especially when developers have something new to bring to the table.

Today, we're looking at Thunder Diamonds 2: Hold and Win, a sequel to Thunder Diamonds and another NeverEnding release featuring relatively new Hold and Win format. Personally, I have a soft spot for Collector-style slots, so I'm curious to see what the developers have prepared this time.

NeverEnding - Slot Developer

NeverEnding entered the iGaming industry in 2025. The studio is headquartered in Limassol, Cyprus, with development operations in Ukraine. The company may be young, but the people behind it already have years of experience in casino game development.

Looking at NeverEnding's catalogue, the developers seem to have a soft spot for classic slot formats and Hold and Win mechanics. There's a fair bit of experimenting with established formulas, too. The studio is still finding its feet in the industry, so I'm curious to see what direction it takes as its catalogue grows.

Slot Theme And Storyline

Visually, Thunder Diamonds 2 doesn't stray far from its predecessor. We still have the same blue backdrop, metallic frame around the reels, and a mix of classic slot symbols with gem-shaped card suits. The most noticeable change is the giant spinning red diamond above the reels, which has grown considerably since the original. Well, at least something got an upgrade.

The sound department hasn't changed much either, with the same familiar effects accompanying the spins. Don't get me wrong, Thunder Diamonds 2 still looks pretty good, and I like its colourful, slightly old-school presentation. However, when a developer puts a big fat "2" in the title, I expect a little more effort on the visual side.

Thunder Diamonds 2: Hold and Win Slot - Reels Screen

Thunder Diamonds 2: Hold and Win Rules and Gameplay

The same situation applies to the basic gameplay. Thunder Diamonds 2 sticks with the compact 3x3 grid and 5 betways that pay from left to right, just like its predecessor. So, anyone familiar with the original should feel right at home here.

The betting range has seen some changes, though. Thunder Diamonds 2 accepts wagers from €0.10 to €50 per spin, with the upper limit reduced compared to the original. I think that's more than enough for most regular sessions, although serious high rollers might find the €50 ceiling a bit restrictive. As usual, betting limits may vary depending on the casino, region, and currency.

Symbols And Paytable

And finally, we get to the additions that give the sequel a reason to exist. As I mentioned earlier, Thunder Diamonds 2 follows the Collector-style Hold and Win formula, so most of the special symbols should already be familiar, especially if you've played the original.

Wild Symbols

Wilds are represented by red Sevens and substitute for all regular paying symbols to help complete winning combinations. They cannot replace Bonus or Thunder Bonus Symbols.

Bonus Symbols

Bonus Symbols appear as diamonds with cash values displayed on them. They can land only on the 1st and 3rd reels, and their values need to be collected by a Collector Symbol on the middle reel to count towards your winnings.

Collector Symbols

Red diamonds act as Collectors and appear exclusively on the middle reel. Whenever one lands, it collects the values of all Bonus Symbols currently visible on the reels. Naturally, the more cash diamonds you have on the screen, the better the payout.

Thunder Collect Symbols

Here's one of the sequel's additions. The yellow Thunder Collect Symbol works much like a regular Collector, with one extra trick: whenever it lands, additional Bonus Symbols appear alongside it. Those values are then collected, so Thunder Collect guarantees a cash prize even if there were no Bonus Symbols on the reels beforehand.

Jackpot Symbols

Some Bonus Symbols carry fixed jackpot prizes instead of regular cash values. They follow the same collection rules, meaning you'll need a Collector to claim them. There are four jackpots available:

• Mini: 25x the total bet
• Minor: 50x the total bet
• Major: 250x the total bet
• Grand: 1,000x the total bet

How To Play Thunder Diamonds 2: Hold and Win For Real Money

Thunder Diamonds 2: Hold and Win is available for real money play at online casinos that carry NeverEnding's games. You can check our casino list above to see which operators offer the slot and accept players from your country.

Thunder Diamonds 2: Hold and Win Bonuses and Special Features

Now, on to the most interesting part of Thunder Diamonds 2. The feature list should look familiar to anyone who's played the original, although NeverEnding has made a few additions to the Bonus Game and expanded the Bonus Buy menu. Let's see what has changed.

Bonus Game

The Bonus Game starts when all three reels contain at least one respective Diamond Symbol. During the round, only diamond symbols appear. Collectors stay in place on the middle reel, collecting the values of Cash Diamonds on the 1st and 3rd reels. The Cash Diamonds then disappear, making room for new symbols on subsequent respins. Every new symbol resets the counter to three, and three consecutive respins without new symbols end the round.

The main addition here is the Multiplier Frames mechanic. These frames can activate randomly during the Bonus Game, highlighting certain positions on the grid. Any symbol landing inside a highlighted cell has its value multiplied by the corresponding frame multiplier. Getting a valuable diamond into one of those positions can make quite a difference to the final payout.

Thunder Diamonds 2: Hold and Win Slot - Bonus Game Screen

Diamond Pile Feature

The Diamond Pile Feature can trigger randomly during both the base game and the Bonus Game. When activated, it adds extra symbols to the reels, including Bonus Symbols, Jackpot Symbols, and Multiplier Frames. The exact additions depend on the activation, giving the feature some extra potential even outside the regular bonus trigger.

Bonus Buy

Thunder Diamonds 2 also comes with a Bonus Buy menu, and this time there are two options to choose from:

• 60x the bet: Triggers the standard Bonus Game.
• 120x the bet: Triggers the Bonus Game with guaranteed Multiplier Frames.

Thunder Diamonds 2: Hold and Win RTP, Volatility, and Max Win

Thunder Diamonds 2: Hold and Win comes with an RTP of 96.08%, exactly the same as its predecessor. That's a decent figure, sitting just above the usual 96% benchmark. So far, so good.

Volatility is rated High, so players should be prepared for potentially lengthy stretches without substantial wins. The Collector mechanics, jackpots, and Multiplier Frames provide several opportunities for larger payouts, although landing valuable combinations may require some patience.

As for the maximum win, NeverEnding has raised the ceiling from the original's 3,000x to 5,000x the bet. A welcome improvement, for sure, although 5,000x still feels a little modest for a High-volatility slot, especially one with several jackpot prizes and multiplier mechanics. The sequel could've aimed a bit higher here.

Thunder Diamonds 2: Hold and Win Demo Version and Free Play

You can play Thunder Diamonds 2: Hold and Win for free here on SlotCatalog without registration or deposits. The demo runs on virtual credits and includes the same Collector mechanics, Thunder Collect Symbols, Diamond Pile Feature, Multiplier Frames, and both Bonus Buy options as the real money version.

It's worth spending some time with the Bonus Game, especially to see how Multiplier Frames interact with Cash Diamonds and jackpot prizes. The demo also gives you room to compare the standard 60x Bonus Buy with the 120x version that guarantees Multiplier Frames. Both can produce very different results, so a few free rounds should give you a better understanding of what you're paying for.

Play Thunder Diamonds 2: Hold and Win On Your Mobile

Thunder Diamonds 2: Hold and Win is available on smartphones and tablets. The 3x3 reelset doesn't demand much screen space, and the symbols are big enough to recognise without much effort. The blue background, metallic frame, and oversized red diamond are all present, although the jackpot counters make the upper part of the screen a little crowded.

Mobile players can access the Bonus Game, Diamond Pile Feature, and both Bonus Buy options. Betting controls and the spin button are accessible through the touchscreen, with no separate app required to play through a compatible mobile browser.

Strategy & Tips For Winning

Thunder Diamonds 2: Hold and Win runs on RNG, so there's no strategy that can change the outcome of a spin. Still, a little common sense goes a long way, especially with real money involved.

• Start with free play. Spend some time observing how the different diamond symbols interact. Pay particular attention to Thunder Collect activations and what happens when several Collectors appear together.
• Keep your bets reasonable. Choose a stake that leaves enough room for multiple spins within your session budget. A few expensive spins can eat through your balance pretty quickly.
• Pay attention to the Multiplier Frames. Their positions matter just as much as their values. A large multiplier won't contribute anything if no suitable symbol lands inside its frame.
• Think twice about Bonus Buy. A purchased round can finish with a payout below its cost. The 120x option is particularly expensive, so consider how much of your balance you're prepared to spend on a single bonus.
• Know when to stop. Decide on your maximum loss before the first spin. Once you reach that figure, call it a day. Increasing your bets after a losing streak won't improve the odds of the next spin.

Pros And Cons Of Thunder Diamonds 2: Hold and Win Slot

Similar Slots To Try

NeverEnding has a few more releases for those who enjoy Collector mechanics, fixed jackpots, and classic slot formats. Ultimate Coins x5000 sticks with a familiar Hold and Win setup, Coin Volt: Charge & Strike adds electrical mechanics to the formula, while Hellcoin Forge takes a darker approach with its bonus-focused gameplay.

• Ultimate Coins x5000: Hold and Win features a 5x3 grid with 15 betways, cash Coins, an Ultimate Hot Coin Collector, and fixed jackpots. The Hold and Win bonus can award up to 5,000x the bet.
• Coin Volt: Charge & Strike uses a compact 3x3 grid with Charge Coins, Coin Surge, and two Bonus Game variants. The Overcharged Bonus introduces Multiplier Frames, while the maximum win is capped at 3,000x the bet.
• Hellcoin Forge: Hold and Win has a 3x3 grid where all payouts come from the Bonus Game. Skull Coins bring Multiplier, Boost, and Catch Frames into play, with a maximum win of 2,000x the bet.

Final Words

I'll admit, I had my doubts about Thunder Diamonds 2: Hold and Win when I first launched it. However, after spending some time with the game, I think NeverEnding has put together a pretty solid sequel. The yellow Thunder Collect Symbols and Multiplier Frames are welcome additions to the original formula, giving the Bonus Game a little more variety.

Are these changes enough to justify putting a big "2" in the title? I'd say yes, although I would've loved to see more work done on the visuals and sound design. The gameplay also remains fairly standard for the Collector-style Hold and Win genre, even with the new mechanics. Still, I had a good time with Thunder Diamonds 2. A fun release overall, just don't expect anything particularly original.