Bob Marlin Goes Deep Slot Review
Yggdrasil Gaming has cultivated a reputation for exploring unconventional mechanics beyond the standard Megaways formula. Bob Marlin Goes Deep, released in July 2025, represents the developer’s commitment to experimental design through a low volatility fishing-themed adventure. The game employs an expanding reel system paired with a collection-based progression mechanic, targeting players who appreciate mechanical novelty over straightforward high-volatility thrills. Whether this unique approach delivers sufficient entertainment value remains the central question worth examining.

Base Game & Features
Bob Marlin Goes Deep operates on a 5×4 grid (expandable to 5×7) with 1,024 ways to win at baseline, expanding to 16,807 when fully expanded. The game employs a scatter-triggered expansion system where each bonus symbol landing on the reels adds one additional row to the playing field. This expanding mechanic directly impacts win potential, though in practice the reels more often than not expand by only one or two rows, doing little to dramatically shift base game engagement.

Expanding Reels Mechanic
The core base game feature revolves around expanding reels. Bonus symbols landing on the leftmost, centre, or rightmost reels each trigger one additional row, with a maximum expansion of three extra rows (bringing the grid from 5×4 to 5×7). The expanded configuration resets between base game spins, meaning each spin presents a fresh canvas. Collectible symbols only appear on the newly expanded rows, creating a tactical element where row expansion determines which collection symbols can land.
Symbol Paytable
The base paytable features thematic fish symbols across multiple value tiers. Standard symbols pay for consecutive matches across adjacent reels, with the expanding grid affecting total win potential. The game employs a 2-of-a-kind minimum rule for lower-value symbols, meaning even small expansions can trigger wins. Wild symbols substitute for regular symbols to complete winning combinations, though they remain relatively uncommon during base gameplay.
Bob Marlin Goes Deep Free Spins & Bonus Features
Bob Marlin Goes Deep offers a dual free spins structure combining traditional bonus rounds with a collection-based progression system. This layered approach distinguishes the game mechanically, though execution falls short of delivering the excitement this design framework promises.

Standard Free Spins Mode
Landing three or more scatter symbols anywhere on the reels triggers 10 free spins played on the fully expanded 5×7 grid. The critical limitation here becomes immediately apparent: scatters and collectible symbols do not appear during free spins themselves. This design choice removes the natural progression vectors that define the base game, transforming the feature into a straightforward reel-spinning exercise on an expanded canvas. Notably, the free spins offer no multiplier enhancements or additional modifiers, meaning the max win potential remains static regardless of when it’s achieved.
Collection Free Spins
Unique to Bob Marlin Goes Deep, a four-meter collection system runs parallel to standard gameplay. Each of the four collection metres requires collecting five identical fish symbols to complete. Upon completion, players receive 5 collection free spins featuring super high-paying symbols (2.8x-4x per symbol payouts). These exclusive symbol sets appear only during collection spins, offering enhanced payout potential. The four collection types (blue, green, purple, and orange fish) each unlock their own collection spins, allowing players to gradually trigger multiple bonus rounds through a single session. However, the increased symbol payouts during collection spins don’t substantially move the needle on total win potential given the limited number of spins awarded.
Why Bonus Buy Is Absent
Unlike many contemporary Yggdrasil releases, Bob Marlin Goes Deep does not feature a bonus buy option. All bonus rounds and free spins modes must trigger through natural gameplay. This design choice reflects a broader philosophy toward player experience, though some may view it as a limitation for those seeking immediate feature access.
Our Honest Verdict
Bob Marlin Goes Deep presents a mathematically solid package undermined by mechanical execution and visual presentation. The 96.8% RTP pairs well with low volatility positioning, ensuring regular wins for casual players seeking steady engagement rather than explosive upside. The maximum win of 3,905x stake ranks below expectations for a Yggdrasil release, particularly when considering the expanding reel and collection mechanics fail to generate genuine excitement during testing.
Mechanically, the expanding reels concept shows promise, yet delivery disappoints. Expansions typically add only one or two rows, providing incremental improvements rather than dramatic shifts in win potential. The base game trundled along at a slow pace with minimal engagement between feature triggers. The collection system introduces progression mechanics appreciated conceptually, though the payout frequency and consistency don’t justify the mechanical complexity.
Visually, the home screen presents an attractive underwater environment with a friendly aesthetic. However, the in-game graphics lack the dynamic immersion found in superior Yggdrasil titles like Lucky Apocalypse. The fishing theme, whilst thematic, doesn’t compensate for mechanical shortcomings. Competitors such as 4 Fantastic Fish and Fish ‘n’ Nudge Big Catch deliver more compelling aesthetic experiences within the niche fishing category.
Bob Marlin Goes Deep appeals primarily to players with strong appreciation for experimental mechanics and simple, straightforward gameplay over visual spectacle. The game will more than suffice for those exploring Yggdrasil’s broader catalogue and seeking low volatility stability. However, fans expecting the developer’s signature feature richness or substantial win potential should look elsewhere within the portfolio.
Bob Marlin Goes Deep FAQs
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What is the RTP of Bob Marlin Goes Deep?
The theoretical RTP of Bob Marlin Goes Deep is 96.8% for the default version, with lower variants at 94.0% and 90.5% available for operators. The 96.8% RTP sits above industry average and provides solid long-term player value for casual players. -
What is the maximum win on Bob Marlin Goes Deep?
The maximum win on Bob Marlin Goes Deep is 3,905x your stake. This max win potential can be achieved during either the base game or free spins modes. During Collection Free Spins, super high-paying symbols award 2.8x-4x per 5-of-a-kind combination, contributing to this total potential. -
Does Bob Marlin Goes Deep have free spins?
Yes, Bob Marlin Goes Deep offers two distinct free spins modes. Standard Free Spins trigger when landing 3 scatter symbols, awarding 10 free spins on the fully expanded 5×7 grid. Collection Free Spins trigger upon completing any of the four collection metres, awarding 5 free spins with exclusive super high-paying symbols (2.8x-4x payouts). -
What is the volatility of Bob Marlin Goes Deep?
Bob Marlin Goes Deep has low volatility, meaning wins come more frequently but are generally smaller in size. The game is designed for casual players preferring steady, frequent wins over high-risk experiences. The 96.8% RTP complements this volatility profile, providing reliable long-term value for players seeking consistent engagement rather than explosive win potential. -
How do the expanding reels work in Bob Marlin Goes Deep?
Each Bonus symbol landing on the playing area expands the grid by one additional row. The maximum height of the field is 7 rows (5×7 formation). Collectible symbols appear only on rows added by the expanding reels feature. This creates between 1,024 and 16,807 ways to win depending on grid expansion. The expanded grid resets between base game spins. -
What are the collection metres in Bob Marlin Goes Deep?
Bob Marlin Goes Deep features 4 collection metres positioned adjacent to the grid. Each metre requires collecting 5 units of a specific fish type (blue, green, purple, or orange) to complete. Upon completion, players trigger 5 Collection Free Spins with exclusive super high-paying symbols (2.8x-4x per 5-of-a-kind) corresponding to that fish type. Multiple metres can be completed across different sessions. -
Can I play Bob Marlin Goes Deep on mobile?
Yes, Bob Marlin Goes Deep is fully optimised for mobile play. The game is built using HTML5 technology, ensuring smooth and seamless gameplay across iOS and Android devices on both tablets and smartphones. Full functionality is preserved across all platforms. -
Does Bob Marlin Goes Deep have a bonus buy feature?
No, Bob Marlin Goes Deep does not feature a bonus buy option. All bonus rounds and free spins modes must trigger naturally through regular gameplay by landing the required symbols or completing collection metres. This design choice emphasises organic gameplay progression over immediate feature access.


