Evoplay previews The Castle of Slotenstein with three Halloween boosters

Evoplay is preparing to bring a distinctly spooky atmosphere to its casino games portfolio with The Castle of Slotenstein, a Frankenstein-inspired video slot built around three coloured boosters and a Hold & Win bonus feature. Combining a classic monster story with a layered bonus structure, the game introduces a series of interconnected mechanics designed to give the bonus round a sense of progression.

Set inside the eerie castle of an ambitious fictional scientist, the game features a towering monster, glowing pumpkins and a collection of symbols that influence how the bonus round develops. The central concept revolves around three boosters, each with a different function, alongside a special end-stage feature known as the Grand Reel of Fortune.

The title is listed by Evoplay as an October 2026 release and is currently marked as coming soon on the provider's official game page. Its Halloween theme places it within the seasonal slot category, while its mechanics provide the main point of distinction.

A Frankenstein-inspired setting with a distinctive bonus structure

The Castle of Slotenstein draws on familiar elements of classic monster fiction. A mysterious doctor, an isolated castle and an imposing creation establish the setting, giving the game a supernatural atmosphere without making the narrative unnecessarily complicated.

Rather than relying exclusively on its visual theme, the slot connects its pumpkin symbols directly to the gameplay. Green, purple and blue Bonus symbols are associated with the Shock, Trick and Treat boosters. Their presence during the triggering spin determines which additional mechanics are available when the Bonus Game begins.

This approach links the Halloween presentation to the game's underlying structure. The coloured pumpkins do more than reinforce the seasonal theme. Each can influence the number of spins, the placement of symbols or the values displayed across the bonus grid.

The official listing identifies the title as a video slot with 20 paylines and a published return to player (RTP) figure of 96.02%. RTP represents a theoretical long-term measure and should not be interpreted as a prediction of individual results. Actual availability and applicable game settings may also depend on the operator and jurisdiction.

Three boosters create different gameplay possibilities

The green Shock booster provides an additional Bonus Game spin. When active, it increases the opening allowance from three spins to four, giving the feature an extra opportunity to develop.

The purple Trick booster focuses on symbol placement and value changes. It allows Purple Bonus symbols to appear during the bonus round, fill available positions and increase the values of Orange Bonus symbols on the same reel. These effects can influence how quickly a reel becomes complete and how its displayed values develop.

The blue Treat booster adds another layer to the feature by applying the value of each Blue Bonus symbol to every Orange Bonus symbol already present on the game field. This creates a different route for changing the bonus grid's accumulated values.

The three mechanics serve separate purposes. Shock changes the available time within the bonus round, Trick affects individual reels and symbol values while Treat distributes additional value across the existing Orange Bonus symbols.

The active boosters depend on the coloured Bonus symbols present on the reels during the triggering spin. Consequently, the bonus round can begin with one, two or all three boosters active. This means the available mechanics can differ between feature entries.

How the Hold & Win bonus game works

The Bonus Game begins with three or four spins, depending on whether the Shock booster is active. Only Bonus symbols appear on the reels during this stage.

Each newly landed Bonus symbol resets the spin counter, allowing the feature to continue while further symbols arrive before the counter expires. The mechanic places the emphasis on completing reels and managing the changing layout of the bonus grid.

A reel is completed when Bonus symbols occupy all three available positions. Once that happens, the values displayed on those symbols are added to the win meter before the reel is cleared.

Clearing a completed reel makes its positions available for new Bonus symbols. This allows the feature to continue building rather than leaving every completed position permanently occupied. The process also connects the reel-filling mechanic to the game's additional progression system.

The first time a reel is completed, its corresponding section of the Grand Reel of Fortune is unlocked. Completing reels therefore contributes to two parts of the feature: the accumulation of displayed symbol values and progress towards the final prize spin.

The game combines these objectives in a straightforward sequence. Players follow the symbols as they land, monitor the active boosters and see whether further completed reels unlock more sections of the special feature.

Grand Reel of Fortune adds a final objective

The Grand Reel of Fortune provides an additional objective beyond collecting values during the main bonus round. It contains five sections, each associated with the first completion of a corresponding reel.

Unlocking all five sections awards one final spin at the end of the Bonus Game. That spin determines one of eight possible prizes.

The listed outcomes include multipliers of 2x, 3x, 5x and 8x, alongside the Mini, Mega, Super and Grand prizes. The final outcome depends on the game's prize mechanism and is not guaranteed by completing the feature.

This progression system gives the Bonus Game a defined end-stage target. Individual reels contribute to the win meter while also advancing the route towards the Grand Reel of Fortune.

The relationship between the two systems provides the feature with a clear sequence of objectives. Players can follow the collection of symbol values while also tracking progress towards the final spin.

Bonus Buy offers direct access to the feature

The Castle of Slotenstein also includes a Bonus Buy option. Where the feature is available through an operator, this option allows players to purchase direct entry into the Bonus Game rather than relying exclusively on triggering it through regular gameplay.

The feature provides a choice of entering with one, two or all three boosters active. This offers alternative configurations for the bonus round while retaining the same basic reel-completion and Grand Reel of Fortune mechanics.

However, direct entry does not remove the uncertainty associated with the game's prize outcomes. The selected boosters determine which mechanics are active, but they do not guarantee a particular return or final prize.

Availability of Bonus Buy can depend on local regulations and the policies of individual operators. Players should check the applicable terms and confirm which features are permitted in their jurisdiction before using the option.

Ivan Kravchuk comments on the new release

Ivan Kravchuk, CEO at Evoplay, said: “The Castle of Slotenstein, gives the classic Frankenstein story an Evoplay twist, combining a spooky Halloween setting with a feature set designed to keep the action building.

“The three boosters each change the way the Bonus Game develops, while the Grand Reel of Fortune gives players a target to chase as they work through the feature. It makes for a suitably unpredictable addition to our portfolio just in time for scary season.”

The comments highlight the combination of seasonal presentation and feature-based progression at the centre of the release. The game's structure places particular emphasis on the interaction between the three boosters and the five-part Grand Reel of Fortune.

Conclusion: A seasonal slot built around progression

The Castle of Slotenstein brings together a recognisable monster-inspired setting and a layered Hold & Win feature. Its three pumpkin boosters provide distinct functions, with additional spins, reel-specific changes and field-wide value additions shaping the bonus round.

The Grand Reel of Fortune adds a longer-term objective by rewarding players for completing all five sections with a final prize spin. The Bonus Buy option also provides a direct route into the feature with different booster configurations, subject to availability.

For Evoplay, the title represents another entry in its seasonal game portfolio. Its defining characteristics are the connection between coloured symbols and gameplay functions and the progression from individual reel completions to the final bonus outcome.

The game's Halloween presentation may attract attention during the seasonal period, but its broader identity rests on its interconnected bonus mechanics. As with all casino slots, its potential outcomes remain uncertain. The published RTP is a theoretical measure rather than a promise of individual results and players should review the applicable game information and use responsible gambling advice when making decisions about play.

FAQs

What is The Castle of Slotenstein?
The Castle of Slotenstein is a Frankenstein-inspired video slot developed by Evoplay. It combines a Halloween-themed setting with three boosters and a Hold & Win bonus feature.

Who developed The Castle of Slotenstein?
Evoplay is the game developer. The provider's official game listing identifies the studio as responsible for the title.

What are the three boosters in The Castle of Slotenstein?
The three boosters are Shock, Trick and Treat. They affect the number of bonus spins, the placement and values of symbols and the values of Orange Bonus symbols across the game field.

How does the Shock booster work?
Shock increases the initial number of Bonus Game spins from three to four when the booster is active.

What does the Trick booster do?
Trick allows Purple Bonus symbols to appear during the bonus round. These symbols can fill empty positions and increase the values of Orange Bonus symbols on their reel.

How does the Treat booster affect the bonus round?
Treat adds the value of each Blue Bonus symbol to all Orange Bonus symbols already present on the game field.

How does the Hold & Win feature work?
The feature begins with three or four spins. New Bonus symbols reset the counter, while filling all three positions on a reel collects their displayed values and clears the reel.

What is the Grand Reel of Fortune?
The Grand Reel of Fortune is a five-section progression feature. Unlocking every section awards one final spin for one of eight possible prizes.

Does The Castle of Slotenstein include a Bonus Buy option?
Yes. The listed feature allows direct entry into the Bonus Game with one, two or all three boosters active, subject to operator availability and applicable regulations.

What RTP is listed for The Castle of Slotenstein?
Evoplay's official game listing gives an RTP of 96.02%. This is a theoretical long-term figure and does not guarantee a particular result for any individual player.

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