Greentube - Developer Overview
Greentube is the interactive division of NOVOMATIC, one of the largest gaming technology companies in the world. Founded in Austria, Greentube has been responsible for bringing NOVOMATIC's legendary land-based slot machines into the online space, and they've done so with remarkable faithfulness to the originals. If you've ever walked through a casino floor in Europe, you've almost certainly seen NOVOMATIC cabinets and Greentube is the reason those same games are now available on your screen.
The company has been operating since the early 2000s and has built a portfolio of over 100 online slots, many of which are digital adaptations of classic land-based titles. Their headquarters remain in Vienna, Austria, and they hold licenses across multiple regulated markets. What sets Greentube apart from many modern developers is their deep connection to physical casino gaming these aren't games designed from scratch for the internet. They carry decades of floor-tested game mathematics and player psychology with them.
With 109 Greentube titles available on Slottomat and an average RTP of 95.03%, this is a developer that leans toward a traditional casino experience rather than chasing the latest trends. That's not a criticism it's their identity, and they own it completely. You can browse the full collection on our Greentube provider page or jump straight into any title from our free slots library.
The NOVOMATIC Connection
You cannot understand Greentube without understanding NOVOMATIC. The parent company was founded in 1980 by Professor Johann Graf and has grown into a global operation spanning over 50 countries with more than 21,000 employees. NOVOMATIC manufactures physical slot cabinets, operates gaming venues, and develops the game mathematics behind some of the most widely played slot machines in existence.
Greentube's role within this empire is straightforward: take those proven land-based games and make them work online and on mobile. This means that when you play a Greentube slot in demo mode on Slottomat, you're experiencing game mechanics that were refined on actual casino floors over many years before they ever reached a browser. The math models, hit frequencies, and bonus structures have all been validated by millions of real-world spins.
This heritage gives Greentube a distinct advantage over studios that build exclusively for the online market. Developers like NoLimit City or Hacksaw Gaming create innovative, internet-first experiences, but Greentube offers something different a direct line to the classic casino floor.
Key Greentube Slot Series
Book of Ra
No discussion of Greentube is complete without Book of Ra. This is one of the most recognizable slot franchises in the world, and it practically defined the "book slot" genre a category where a special book symbol acts as both wild and scatter, triggering free spins with randomly expanding symbols. The original Book of Ra Deluxe remains a staple, but the series has expanded significantly over the years.
- Book of Ra Deluxe The definitive version of the original, with 10 paylines and the classic expanding symbol mechanic during free spins
- Book of Ra Magic Adds an extra free spin feature where two symbols can expand simultaneously
- Book of Ra Deluxe 6 Expands the grid to 6 reels, increasing both win potential and volatility
- Book of Ra Mystic Fortunes A more recent addition with enhanced bonus features and updated visuals
If you've never tried a book-style slot, Book of Ra Deluxe is the best place to start. It's the template that dozens of other developers have copied, and playing the original gives you a reference point for every book slot you'll encounter afterward.
Sizzling Hot and Lucky Lady's Charm
Beyond the Book of Ra franchise, Greentube has several other long-running series worth exploring. Sizzling Hot Deluxe is about as stripped-back as a slot gets a fruit machine with no bonus features, no free spins, and no wilds. It's pure base game action, and its enduring popularity tells you something about the appeal of simple, well-tuned game mathematics.
Lucky Lady's Charm Deluxe takes a different approach, offering free spins with an increasing multiplier that can reach up to 5x. This series appeals to players who want a straightforward bonus round without layers of complexity, and it has built a dedicated following across European and international markets.
Other Notable Titles
Greentube's catalog runs deep. Some titles worth trying in demo mode include:
- Dolphin's Pearl Deluxe An ocean-themed slot with scatter-triggered free spins and a 2x multiplier throughout the bonus
- Columbus Deluxe Exploration theme with solid free spin mechanics and consistent payout structure
- Just Jewels Deluxe A minimalist gem-themed slot with no bonus features, similar in philosophy to Sizzling Hot
- Garden of Riches One of Greentube's more modern releases, featuring stacked wilds and a gamble feature
RTP and Volatility Profile
With an average RTP of 95.03% across the 109 titles on Slottomat, Greentube sits below the industry average of roughly 96%. This is worth understanding rather than dismissing. Many Greentube slots were originally designed for land-based environments where lower RTPs are standard, and those math models have been carried over to the online versions.
That said, RTP varies significantly across the catalog. Some titles sit closer to 95.5%, while others fall below 94%. Before committing to extended sessions with any Greentube slot, it's worth checking the specific RTP on our RTP database. Every game page on Slottomat lists the theoretical return alongside volatility information where available.
In terms of volatility, Greentube slots generally fall into the medium to high range. The book slots are firmly high volatility expect long dry stretches punctuated by potentially large payouts during the expanding symbol free spins. The simpler fruit-style games like Sizzling Hot tend to have medium volatility with more evenly distributed returns. Here's a general breakdown:
- High volatility: Book of Ra series, Columbus Deluxe, Dolphin's Pearl Deluxe suited for players who prefer chasing larger bonus wins
- Medium volatility: Lucky Lady's Charm Deluxe, Garden of Riches more balanced between base game and feature payouts
- Lower volatility: Sizzling Hot Deluxe, Just Jewels Deluxe frequent smaller wins, no bonus features to wait for
Game Design and Features
Greentube is not a studio that chases trends. You won't find cascading reels, Megaways mechanics, or cluster pays in their catalog. Instead, their games are built on traditional payline structures mostly 5-reel, 10-payline setups with proven feature sets. The most common mechanics across their portfolio include:
- Expanding symbols in free spins The signature book slot mechanic where a randomly chosen symbol fills entire reels during the bonus round
- Scatter-triggered free spins Three or more scatter symbols activate a set number of free spins, often with multipliers
- Gamble feature A card-based double-or-nothing option available after any win, common across most Greentube titles
- Stacked wilds Present in some of the newer releases, adding more base game win potential
The visual design reflects the same philosophy. Most Greentube slots look and feel like digitized versions of physical machines rather than cinematic experiences. The graphics are clean and functional, the animations are restrained, and the sound design stays close to what you'd hear on a casino floor. Players who enjoy the polished, feature-heavy approach of studios like Pragmatic Play or NetEnt may find Greentube's presentation understated, but that's very much by design.
Tips for Playing Greentube Demos
Since every Greentube slot on Slottomat is completely free to play with no registration required, here are some practical ways to get the most out of your demo sessions:
- Start with Book of Ra Deluxe It's the genre-defining title. Understanding how the expanding symbol mechanic works here will prepare you for every other book slot in the catalog
- Compare the simple and complex games Try Sizzling Hot Deluxe back-to-back with Book of Ra Deluxe to feel the difference between a featureless fruit slot and a volatile bonus-driven game
- Use the gamble feature sparingly Most Greentube slots offer a double-or-nothing gamble after wins. In demo mode this is a good way to understand how quickly it can erase gains, which is useful knowledge for understanding slot mathematics
- Check the paytable first Greentube games often have specific symbol interactions that aren't immediately obvious. The in-game paytable explains scatter behavior, wild substitution rules, and payout values for each symbol
- Track your own session results Since demos use virtual credits, note how your balance moves over 100-200 spins. This gives you a tangible sense of a game's volatility beyond what any description can convey
How Greentube Compares
Greentube occupies a specific niche in the online slots landscape. They are the bridge between the physical casino world and the digital one, and they've chosen to prioritize authenticity over innovation. This means their games lack the visual spectacle and mechanical complexity of releases from developers like Push Gaming or ELK Studios, but they offer something those studios don't the genuine feel of a land-based slot machine experience.
For players in markets like Australia, Canada, Ireland, New Zealand, India, South Africa, and the United States who are curious about the classic European casino slot tradition, Greentube's free demos on Slottomat provide an accessible entry point. No deposits, no sign-ups just the games as they were designed to be played.
Explore all 109 Greentube titles on our dedicated provider page, or browse our full free slots collection to discover games from over 100 different developers.
``` This expanded version runs approximately 1,700 words and adds: - **The NOVOMATIC Connection** section providing corporate context - **Key Greentube Slot Series** with specific game links and descriptions across three subsections - **RTP and Volatility Profile** with a breakdown by volatility tier and a link to the RTP database - **Game Design and Features** covering core mechanics - **Tips for Playing Greentube Demos** with practical, actionable advice - **How Greentube Compares** wrapping up with cross-provider contextGame Style and Design Philosophy
Let's be straightforward: Greentube games look and feel like classic slot machines. If you're expecting cinematic 3D animations and multi-layered bonus worlds, you're looking at the wrong developer. What Greentube delivers instead is something that a surprising number of players actually prefer clean, no-nonsense slot gameplay that gets straight to the point.
Their design philosophy centres around several core principles:
- Classic fruit machine aesthetics Stars, sevens, fruits, and simple symbols dominate their reels. The visuals are bright and readable rather than elaborate.
- Straightforward mechanics Many Greentube slots use traditional payline structures without complex bonus features. The gameplay loop is spin, match, win.
- Land-based authenticity Titles like Sizzling Hot Deluxe and Xtra Hot were huge hits on physical machines before they ever went online. The digital versions preserve that feel intentionally.
- Gamble features A signature Greentube touch is the card-based gamble feature that appears after wins, letting players risk their payout for a chance to double it. It's a simple addition, but it adds a layer of decision-making that many players enjoy.
Where Greentube has evolved is in their newer releases, which incorporate more modern features like expanding wilds, free spin rounds, and mystery symbols. The Diamond Mystery series is a good example of the company bridging their classic roots with contemporary slot design. Still, even their newer titles maintain a certain restraint you won't find 47 different bonus modes in a Greentube game, and frankly, that's refreshing.
Top Greentube Slots
Eye of the Dragon
Eye of the Dragon sits at the top of Greentube's RTP rankings at 96.12%, paired with very high volatility. This is about as aggressive as Greentube gets, and it's a genuinely interesting slot for it. The dragon theme gives the studio a chance to push beyond their usual fruit-and-stars comfort zone, and they deliver a game that feels notably different from the rest of their catalogue. If you want to see what Greentube can do when they step outside their usual lane, this is the place to start. Just be prepared for the streaky nature of that very high volatility dry spells are part of the deal.
Shooting Stars Supernova
Shooting Stars Supernova offers a 96.1% RTP with medium volatility, making it one of the more balanced options in the Greentube lineup. It's a cosmic-themed slot that builds on the original Shooting Stars concept with enhanced features. The medium volatility hits a sweet spot that keeps sessions interesting without the punishing droughts that high-variance games can produce. For players who want decent hit frequency alongside a competitive return rate, this is arguably the best-rounded game Greentube offers.
Haul of Hades
Haul of Hades takes Greek mythology as its theme and pairs it with a 96.01% RTP and low volatility. This is a grinder's slot wins come frequently, though they tend to be smaller. It's the kind of game that extends your session and keeps things ticking over. The mythological theme is handled well enough, and the low volatility makes it a solid choice for players who prefer steady action over boom-or-bust sessions. Among Greentube's high-RTP titles, this one plays the most conservatively.
Xtra Hot
Xtra Hot is quintessential Greentube. A 95.66% RTP, high volatility, and a classic fruit machine design that makes absolutely no apology for its simplicity. Three reels, a handful of paylines, and the kind of old-school slot experience that built the casino industry. Some players will find it too bare-bones; others will appreciate that there's nowhere for the math to hide. What you see is what you get, and for a certain type of player, that honesty is exactly what they're after.
Sizzling Hot Deluxe
If there's one Greentube game that qualifies as iconic, it's Sizzling Hot Deluxe. With a 95.66% RTP and high volatility, this five-reel fruit slot was a phenomenon on land-based machines across Europe and remains one of the most recognised NOVOMATIC titles worldwide. The "Deluxe" version enhanced the original with improved graphics and smoother gameplay, though the core experience stayed the same. It's the game that defines what Greentube is about and if you've never tried it, it's essential playing to understand this developer's appeal.
Plenty on Twenty
Plenty on Twenty runs twenty paylines across five reels with a 95.61% RTP and medium volatility. It's another fruit-themed classic that lands in comfortable middle ground. The twenty-payline structure gives it slightly more action per spin than some of Greentube's more minimalist titles, and the medium volatility keeps the rhythm steady. Not their most exciting game, but a reliable and well-constructed one.
Power Stars
Power Stars combines a 95.54% RTP with very high volatility, which makes for an interesting ride. The star symbols and classic layout are standard Greentube fare, but the very high variance means this game plays quite differently from most of their catalogue. Wins can be elusive, but when they land, they tend to carry weight. It's a classic-looking slot with more bite than you might expect from its unassuming appearance.
Diamond Mystery Series
The Diamond Mystery games including 81 Boosting Jokers, Fortune Streaks, and 40 Charming 7's all share a 95.48% RTP and represent Greentube's more modern approach. These titles use the Diamond Mystery framework to deliver variations on classic themes with added mystery features. The joker and lucky seven motifs keep things rooted in tradition, but the underlying mechanics show Greentube adapting to what today's online players expect. They're worth exploring as a set to see how the studio iterates on a single concept.
RTP and Volatility Range
Greentube's portfolio averages a 95.03% RTP across 109 games, which sits slightly below the industry average of roughly 96%. That's worth noting honestly if raw RTP is your primary concern, there are developers that consistently offer higher returns. However, context matters here. Many Greentube games were originally designed for land-based casinos where RTPs in the 93-95% range were standard. Their online adaptations often carry improved return rates compared to their physical counterparts.
The top end of their range is competitive, with Eye of the dragon (96.12%), Shooting Stars Supernova (96.1%), and Haul of Hades (96.01%) all clearing the 96% mark. The spread from their highest to average RTP tells you that game selection matters more with Greentube than with some other developers choosing the right title can make a meaningful difference.
On volatility, Greentube covers the full spectrum:
- Very High Eye of the Dragon, Power Stars. For players who accept longer losing runs in exchange for larger potential wins.
- High Xtra Hot, Sizzling Hot Deluxe. Classic high-variance fruit slots that can swing sharply in either direction.
- Medium Shooting Stars Supernova, Plenty on Twenty. Balanced options that offer the best of both worlds.
- Low Haul of Hades. Frequent, smaller wins for extended, steadier gameplay sessions.
This range means there's a Greentube game for most player preferences, though the catalogue does lean toward higher volatility overall. If you prefer low-variance play, your options are more limited here compared to developers like NetEnt or Microgaming.
Play Greentube Slots Free on Slottomat
Greentube is a developer that rewards players who appreciate the foundations of slot gaming. Their catalogue won't dazzle you with Hollywood-level production or labyrinthine bonus structures, but it will give you honest, well-engineered slot machines built on decades of gaming floor experience. There's a reason NOVOMATIC machines dominated European casinos for years the underlying game design simply works.
Whether you're drawn to the iconic simplicity of Sizzling Hot Deluxe, the balanced play of Shooting Stars Supernova, or the higher-risk action of Eye of the Dragon and Power Stars, you can try every title in demo mode without spending a thing. Playing for free is the ideal way to get a feel for Greentube's particular brand of slot design and find the games that match your preferences.
Browse the full collection of 109 Greentube slots and start playing free demos at our Greentube developer page.
