Oxygen 2 (ELK Studios) – Review & Demo Play

The Oxygen 2 Slot Game

I head back to the seabed with Oxygen 2 from ELK Studios, a 6x7 cluster pays slot where wins form from 5+ matching symbols touching vertically or horizontally. The see-through grid floats in a shadowy wreck-like grotto dotted with coral and pipes. Bets span 0.20 to 100. Avalanches clear wins and drop fresh symbols. Oxygen Bubbles sit at the heart of play, while jellyfish, octopus, and special wilds stir the pot. It's high volatility, 94% RTP, and capped at 25,000x.

Symbols and Payouts in Oxygen 2

Clusters pay via a tidy set of themed icons. Low pays are green, orange, and pink floaters. At 16+ in a cluster they award 10x, 15x, and 20x the bet, while 5-of-a-kind pays start from 0.1x for the smallest wins. The avalanche flow evaluates each cluster as prize times stake, then clears the grid. Symbols can also arrive oversized, filling 2x2, 3x3, or 4x4 blocks that help bind clusters across rows and columns.

Premiums are a green snail, orange crab, pink fish, and red octopus. For 16+ these pay 25x, 30x, 50x, and 100x, with smaller cluster tiers scaling down accordingly. Wilds substitute for any pay symbol, and an all-wild win pays like the top premium. Big symbols can carry multipliers, which interact with Oxygen Bubbles for spicy totals. This set-up gives clean paytable scaling without clutter, and it keeps the grid legible even when avalanches chain for a while.

Oxygen 2 Symbols and Paytable

Symbol	Quantity	Payout
	16+	x100
	13+	x10
	10+	x5
	8+	x2.5
	6+	x1.5
	5	x1
	16+	x50
	13+	x5
	10+	x3
	8+	x1.5
	6+	x0.75
	5	x0.5
	16+	x30
	13+	x4
	10+	x2.5
	8+	x1.2
	6+	x0.6
	5	x0.4
	16+	x25
	13+	x3.5
	10+	x2
	8+	x1
	6+	x0.4
	5	x0.3
	16+	x20
	13+	x3
	10+	x1.5
	8+	x0.8
	6+	x0.25
	5	x0.2
	16+	x15
	13+	x2.5
	10+	x1.25
	8+	x0.6
	6+	x0.2
	5	x0.15
	16+	x10
	13+	x2
	10+	x1
	8+	x0.5
	6+	x0.15
	5	x0.1

Oxygen 2 Slot Bonus Features

When a winning symbol first explodes, its position activates as an Oxygen Bubble at x1. Each later explosion on that spot doubles the value, up to x2,048. Bubbles don't tumble, so you can stack values during a round. Multiplier Strike can kick in on any drop, splashing random multipliers onto the grid to seed more hot spots. Hitting wins across activated positions totals their values into the cluster win, which is where the slot can erupt.

Jellyfish may swim in carrying a multiplier. They pause over several random positions, adding their value to those spots. If they land on a spot that already holds a value, the numbers add both ways, which can turn middling setups into genuine threats. The Octopus sits behind one position. If that position joins a win, it snatches a random selection of available multipliers outside the cluster and adds them to the current win multiplier for that hit.

Exploding Wilds clear two cone-shaped lanes from their centre, setting off avalanches. Super Exploding Wilds also activate any inactive Bubbles they blow through. Blaster Wilds pop in a plus or X pattern, replacing affected symbols with a chosen pay or wild symbol; overlaps turn into wilds. Three scatters award 10 Free Spins with Bubble multipliers and the Octopus persisting between spins. Four scatters launch the Super Bonus with a jellyfish every spin. Retriggers grant +3, +5, or upgrade with +7. X-iter buys sit at 3x, 10x, 25x, 100x, and 500x.

Bonus Buy Feature

Bonus Hunt Increase your chance to trigger the bonus game by three times.
Feature Cost:	x3 Bet
RTP:	-
Volatility:	-
Special Wilds Guarantees one spin with at least three Wild symbols.
Feature Cost:	x10 Bet
RTP:	-
Volatility:	-
Octo Strike One spin with guaranteed Octopus and Multiplier Strike.
Feature Cost:	x25 Bet
RTP:	-
Volatility:	-
Bonus Game Free Spins with guaranteed Octopus feature on every spin.
Feature Cost:	x100 Bet
RTP:	-
Volatility:	-
Super Bonus Game Super Free Spins with guaranteed Octopus Feature and Jellyfish Feature on every spin.
Feature Cost:	x500 Bet
RTP:	-
Volatility:	-

How to Win at Oxygen 2 Slot

I start by setting a stake that suits a long session, then let avalanches work while I track activated Bubbles. If the grid seeds values on central lanes, I stick around and ride the momentum; if it looks barren, I reset or use Bonus Hunt to chase features. The special wilds buy can be handy for forcing interaction. During Free Spins, I target longer runs rather than quick exits, since persisting multipliers and the roaming Octopus snowball over time.

Oxygen 2 Slot RTP & Volatility

Oxygen 2 runs a 94% RTP with high volatility and a 25,000x max. Swings can be steep, as Bubble doubling needs repeat hits on the same spots. Random features seed value, yet dry spells happen, especially in base play. I found sessions ebb and flow around how many activated positions you carry into cascades. That profile suits bankrolls built for variance and players chasing rare, larger outcomes rather than frequent nudges. Short sessions can feel spiky; longer sets even things out a touch.

For me, the rhythm is about staging. I pace bets, avoid chasing after a dead grid, and reserve buys for moments that line up with my bankroll. The 3x Bonus Hunt is handy for volume play, while 25x Octo Strike sets up a punchy single spin with multipliers in circulation. The standard bonus at 100x offers steady value via persistent Bubbles and an Octopus each spin. The 500x super buy piles on jellyfish, but variance bites harder.

The Final Thoughts on Oxygen 2

Oxygen 2 keeps the core bubble loop intact and adds lively helpers. Jellyfish and Octopus can turn a plain board into a proper setup, though jellyfish animations can slow the tempo when they whiff. I rate the regular bonus over the super most days, then hope for an upgrade. It isn't a giant leap from the first outing, yet the 6x7 cluster grid, special wild interplay, and 25,000x ceiling make it well worth a punt.