Oxygen 2

ELK Studios brings a second installment to its underwater-themed slot series, building on the foundation established by the original Oxygen from 2023. This follow-up takes players back into the depths of the ocean for another round of exploration and potential payouts. The setting presents a submarine grotto filled with crumbling wreckage, coral formations, and sandy expanses that create an immersive environment. Rather than simply recycling what came before, the developers have tweaked the formula around its edges to introduce fresh dynamics while preserving the most effective elements that made the first game resonate with audiences.

Gameplay and Layout

The slot operates on a 6-column, 7-row grid where symbols cascade downward in a cluster-based system. Winning combinations form when five or more matching symbols land adjacent to each other either horizontally or vertically. Players can select wagers ranging from 0.20 to 100 per spin, with game mechanics that remain consistent regardless of chosen bet level. The visual design features a transparent gaming grid positioned against the murky underwater backdrop, allowing the depth effect to enhance the immersive quality. Character symbols and colorful floating objects make up the pay table, with different tiers offering escalating rewards based on cluster size.

The Mathematics

With an RTP of 94 percent and high volatility at play, Oxygen 2 presents a challenging mathematical landscape that demands patience and substantial bankroll management. Small clusters pay modestly, with five symbols generating between 0.1 to 1 times the wagered amount. However, larger formations deliver significantly more substantial returns, with clusters exceeding sixteen symbols reaching 10 to 100 times the stake. Wild symbols substitute for standard pay icons and can generate winning combinations in their own right. The payoff structure encourages the accumulation of increasingly powerful symbols across multiple consecutive wins rather than relying on single massive clusters.

The Multiplier System and Bonus Mechanics

At the core of gameplay sits a multiplier mechanism tied to oxygen bubble positions. When symbols explode during winning combinations, they activate bubbles at their grid locations. Subsequent explosions occurring on these bubble spaces trigger a doubling of the multiplier value, theoretically reaching as high as 2,048 times on individual positions. The Multiplier Strike feature occasionally triggers without warning, randomly placing additional multipliers across the grid to amplify winning potential. These mechanics create situations where previously modest wins can transform into substantial payouts as cascades continue and multipliers stack. The Jellyfish feature independently manifests on certain spins, carrying its own multipliers and traveling across multiple grid positions before coming to rest. When a Jellyfish reaches an existing multiplier, both values combine, creating multiplicative rather than additive gains. The Octopus mechanism functions differently, stationing itself behind a specific grid position and activating when that location participates in a winning cluster.

Wild Variations and Feature Interactions

Two distinct wild variants introduce additional complexity to winning scenarios. The Exploding Wild detonates when part of a winning cluster, clearing all regular pay symbols within cone-shaped zones extending left, right, up, and down from its position. This clearing action simultaneously activates any Super Exploding Wilds in those zones, which then trigger all dormant oxygen bubbles in the affected areas. The Blaster Wild takes a different approach, selecting a random symbol and replacing all matching icons in either X or plus-shaped patterns across the grid. Any wilds caught in multiple Blaster patterns convert into additional wild symbols, compounding their impact. These mechanisms encourage experimentation and allow for surprising win explosions during seemingly ordinary spins.

Free Spins and Purchase Options

Reaching three scatter symbols in base gameplay grants ten free spins, during which all oxygen bubbles and their accumulated multipliers persist between turns. Hitting four scatters activates an enhanced version called the super bonus game, which triggers the Jellyfish feature before each free spin. The octopus also carries forward its position through free spins, repositioning randomly at the start of each round. Retriggering is possible when additional scatters land, awarding three or five extra spins depending on count. The X-iter menu allows purchase of various bonus modes outside the normal flow. Bonus Hunt increases the likelihood of triggering free spins by three times but costs three times the wager. At ten times the bet, players can buy a spin that guarantees at least three special wilds. Octo Strike costs twenty-five times the stake and ensures both an Octopus appearance and at least one Multiplier Strike on the spin. The standard free spins bonus can be purchased outright for one hundred times the bet, while the premium super bonus with Jellyfish features on each free spin demands five hundred times the wager. The maximum potential win across all modes reaches twenty-five thousand times the initial stake.

Final Assessment

Oxygen 2 stands as a competently constructed cluster-based slot that delivers on technical execution. Whether ELK Studios drew inspiration from Pragmatic Play's Sugar Rush remains unclear, but the team certainly absorbed key lessons about what makes such mechanics engaging. The oxygen bubble multiplier system proves effective here just as it worked previously, with the potential for exponential growth keeping players engaged throughout sessions. However, the expanded feature set creates occasional friction. The Jellyfish mechanic, while visually appealing and mechanically interesting, moves deliberately across the grid, sometimes slowing the game's rhythm when it fails to connect. Its gradual movement arguably builds tension and anticipation, so this trade-off may benefit certain player preferences. The slot neither dramatically improves upon its predecessor nor disappoints by merely duplicating it. Instead, it represents a measured step sideways, expanding the feature ecosystem while maintaining what functioned well originally. The additional mechanics breathe new life into the formula without completely reinventing the wheel.

Not sure what a figure means? The glossary explains RTP, volatility and max win in plain English.