Sunken City Riches Review: Features, RTP & Bonuses

Sunken City Riches is an upcoming video slot from Stakelogic set in a legendary underwater city filled with hidden treasures. Its standout feature is a dual progression system that gradually unlocks new mechanics and rewards throughout the each session.

Sunken City Riches Key Data

With 1,024 Payways, Very High volatility, an RTP of 96.01%, and a maximum win of 15,000× (€450,000), Sunken City Riches is designed around long-term progression rather than isolated bonus rounds.

How Sunken City Riches Works

Sunken City Riches Base Game

Sunken City Riches is built around two independent progression systems that evolve simultaneously throughout the session. Every Treasure Map Scatter contributes to both meters at the same time: the Treasure Map Meter unlocks permanent gameplay features, while the Gem Meter collects multiplier values that eventually trigger a separate bonus game.

Treasure Map Meter Progression

The Treasure Map Meter tracks collected Treasure Map Scatter symbols and unlocks a new gameplay feature after every four Scatters collected. Unlike temporary bonus mechanics, these features remain available for the rest of the session and can trigger randomly during future spins, gradually expanding the gameplay throughout the session.

Sunken City Riches Treasure Map Meter Progression

Treasure Map Features

As players progress through the Treasure Map Meter, four gameplay features are unlocked one by one. Once unlocked, each feature can trigger randomly during future spins, gradually expanding the gameplay instead of being confined to a single bonus round.

• Payway Maker: Selects one symbol on the first reel and copies it across the remaining reels to create additional winning combinations before wins are evaluated.
• Symbols Upgrade: Upgrades one randomly selected paying symbol to the highest-value symbol currently on the reels, potentially creating additional wins.
• Wild Multipliers: Adds 1–3 Wild symbols with multipliers ranging from 1× to 5×, increasing the value of any wins they help complete.
• Split Symbols: Splits 1–10 randomly selected symbols on the reels, creating additional winning opportunities.

Sunken City Riches Treasure Map Features

Each Treasure Map Feature is introduced by a short monkey animation. Depending on the unlocked mechanic, the companion swings on a vine, throws a banana, looks through a telescope, or simply reacts with a cheerful animation before the feature is applied. While these sequences are purely visual, they clearly indicate which mechanic has been activated.

Free Spins

The Free Spins feature is triggered by landing 3, 4 or 5 Scatter symbols, awarding 8, 10 or 12 Free Spins respectively. Retriggers award 3, 4 or 5 additional Free Spins, depending on the number of Scatters landed.

Sunken City Riches Free Spins Feature

Unlike many slot bonuses, Free Spins continue building on the Treasure Map progression system.. All previously unlocked Treasure Map Features remain active, and at least one unlocked feature is guaranteed on every Free Spin, allowing Payway Maker, Symbols Upgrade, Wild Multipliers and Split Symbols to continue modifying the reels throughout the bonus.

Gem Meter Progression

Running alongside the Treasure Map Meter, the Gem Meter collects the multiplier values displayed on Treasure Map Scatter symbols. Rather than unlocking gameplay modifiers, it stores these values until enough Gems have been collected to activate a separate bonus feature.

Once the meter reaches 20 collected Gems, the accumulated multipliers are carried into the Mystery Pick Bonus, creating an additional reward cycle that progresses independently from the Treasure Map system.

Mystery Pick Bonus

Sunken City Riches Mystery Pick Bonus Board

The Mystery Pick Bonus begins after collecting 20 Gems in the Gem Meter. All stored multiplier values are transferred onto a board containing 20 hidden gears, where each selection reveals one of the accumulated prizes.

The bonus continues until the Collect Gear is uncovered. At that point, all previously revealed multiplier values are added together and awarded as the final prize for the feature. Unlike the Treasure Map progression, which permanently expands the base game, the Mystery Pick Bonus periodically converts stored Gem values into a standalone pick-style bonus.

Sunken City Riches RTP, Super Stake and Buy Bonus

Sunken City Riches has an RTP of 96.01%, Very High volatility, and a maximum win of 15,000× the bet (€450,000). The game’s mathematical model focuses on its interconnected feature system, with Treasure Map Features, the Gem Meter and Free Spins all contributing to its long-term winning potential.

Players can also activate Super Stake, increasing the total bet by 50% to improve the chances of landing Scatter symbols and triggering the Free Spins feature. Alternatively, the Buy Bonus option grants immediate access to Free Spins for 100× the total bet.

Pros & Cons

Pros

• Two independent progression systems that evolve simultaneously
• Treasure Map Features permanently expand the gameplay as the session progresses
• Mystery Pick Bonus adds a separate reward cycle
• Free Spins keep all unlocked Treasure Map Features active
• Maximum win of 15,000×

Cons

• Treasure Map Features require gradual progression before all mechanics become available
• Mystery Pick Bonus depends on filling the Gem Meter
• Very High volatility may result in longer gaps between larger wins

Final Thoughts about Sunken City Riches

Sunken City Riches stands out by treating progression as the heart of its gameplay rather than a single bonus feature. Instead of building toward one major event, players gradually unlock new Treasure Map mechanics while simultaneously filling the Gem Meter for the Mystery Pick Bonus. Combined with feature-rich Free Spins and a maximum win of 15,000×, the result is a slot that keeps evolving throughout the session instead of resetting after every bonus.