Jungle Jim and the Lost Sphinx Slot Review
Most expanding-grid slots make you wait for a bonus to see the bigger board. Jungle Jim and the Lost Sphinx doesn’t: win often enough in the base game and the temple physically unlocks around you, a fifth row arriving with fifteen extra paylines mid-chain. It’s a rolling-reels slot that treats its own geometry as a prize, which is the most interesting thing about it and, when the rolls dry up on roll one or two, the most frustrating.
Stormcraft Studios built Jungle Jim and the Lost Sphinx around that idea. It runs on a 5×4 grid with 35 paylines that expands to 5×5 and 50 paylines when the trail hits 4x or more, at 96.10% RTP (96.30% with the Win Booster), medium volatility, and a 6,250x win ceiling. Jim later found his way back to the jungle in Jungle Jim Gold Blitz, our 2026 review of a harder-hitting sequel. The Sphinx keeps her secrets, but she’s generous with multipliers.
Base Game & Features
Wins pay left to right from the first reel, with matching symbols required on adjacent positions of an enabled payline. Only the highest combination pays on each line, and only the highest scatter combination pays per spin. Scatter and bonus wins are added to regular wins rather than replacing them.
The wild substitutes for other symbols but not the scatter or the Sphinx, and appears only on reels 2 through 5. It can’t form its own winning combination. Scatters don’t need adjacent reels to pay, and the wild can’t stand in for them. Scatter payouts depend on your total bet.
Your stake is built from coins and coin size, then multiplied by a fixed bet multiplier of 10. Two coins at 0.20 coin size works out to 0.40 per betting payline, times the multiplier, for 4 total credits per spin. The bet is calculated on the first 10 paylines, but you play and win on all enabled ones, and the paytable always displays payouts for your current bet.
Rolling Reels
Any win except a scatter combination sets the Rolling Reels in motion. Winning symbols are removed, the symbols above shift down to fill the gaps, and new symbols drop in. If that produces another win, you’re paid again without staking another spin, and the process repeats until a roll comes up empty. Winnings collect automatically throughout, so there’s nothing to bank manually mid-chain.
The Multiplier Trail
Each consecutive roll advances a multiplier trail, and this is where the board itself grows. The values step up as follows:
- Initial spin: 1x at 35 lines
- Roll 1: 2x at 35 lines
- Roll 2: 3x at 35 lines
- Roll 3: 4x and the grid upgrades to 50 lines
- Roll 4: 5x at 50 lines
- Roll 5 and beyond: 10x at 50 lines
The trail stops climbing at its maximum and holds there for the rest of the chain. In practice the jump that matters most is roll 3, because that’s the step where the fifth row arrives and fifteen extra paylines come with it.
Second Chance Respin
If roll 3 produces no win, a Second Chance Respin awards one respin with the trail intact rather than reset. It can only happen once per wager. Should that respin also fail to form a win, the trail goes back to the start and the spin is over. Note the timing: the rescue only exists on the third roll, so a chain that dies on roll 1 or 2 simply ends.
Win Booster
The Win Booster is an optional bet mode you can switch on in the regular game. It places an extra scatter outside the reels, improving the odds of triggering free spins, and it raises the RTP to 96.30%. Activating it changes the per-spin bet multiplier from 10 to 40, so the total stake quadruples. The same two coins at 0.20 coin size would cost 16 total credits per spin instead of 4. Scatter payouts are calculated on the base bet, not the boosted one.
Paytable Achievements
The game also tracks Paytable Achievements: winning every combination for a given symbol highlights that symbol on the paytable permanently, even after you exit the game. Regular symbol wins are what count. Wild and multiplier substitute wins aren’t logged, and neither are free spins wins, so the achievements measure base game form only. It’s a completionist layer rather than a paying feature, and it isn’t available in every build of the game.
Jungle Jim and the Lost Sphinx Free Spins & Bonus Features
Landing three or more scatters anywhere on the reels awards 12 free spins. The expanded grid becomes permanent: all 50 paylines stay enabled for the whole round, and Rolling Reels carry over. The bet that triggered the round determines the free spins stake, and winnings collect automatically throughout. Scatters themselves don’t appear during the round, so everything from here runs on Sphinx collections and rolling chains.
The Free Spins Multiplier Trail
The trail returns in stronger form here, starting at 2x and climbing much higher than the base game version:
- Initial spin: 2x
- Roll 1: 3x
- Roll 2: 4x
- Roll 3: 8x
- Roll 4: 12x
- Roll 5 and beyond: 20x
A losing spin doesn’t send the trail all the way back to the beginning. It resets only to the first visible minimum multiplier, so progress you’ve banked survives. That minimum itself keeps rising, thanks to the feature below.
The Sphinx Symbol
This symbol can only land on reel 3 during the round. Each one is collected and removed from the reel, letting the remaining symbols shift, and each collection does two things: it awards an additional spin and raises the minimum multiplier on the trail. Once the trail’s maximum is reached, further Sphinx appearances still pay out an extra spin, so the symbol never stops earning.
The Stars Feature
At the end of the round you’re rated on how much the free spins paid, measured against your base bet:
- 1 Star: any win above 0x the base bet
- 2 Stars: 10x base bet
- 3 Stars: 45x base bet
- 4 Stars: 150x base bet
- 5 Stars: 450x base bet
It’s a rating, not a payout, and the Win Booster stake isn’t counted in the calculation. A round that pays 10x your base bet earns two Stars, whether or not you paid quadruple stake to get there. The thresholds are steep at the top: 450x in a single round of free spins is a serious result by this game’s standards.
Our Honest Verdict
Overall Rating: 7.8/10
The reason to sit down at this temple is that it keeps unfolding while you’re winning. One decent chain and the place grows a floor, raises its multipliers and, in free spins, lets a Sphinx quietly raise the floor again every time she shows up. That free spins round is the strongest thing here, because a bad spin costs you almost nothing once the minimum multiplier has climbed – the game forgives you for staying.
It’s less forgiving getting there. The base game is slow work between scatters, and the Win Booster, which quadruples your stake for better trigger odds, is priced too steeply to feel like anything but a toll. A chain that dies on roll one or two just ends, and it ends often.
If you like watching a session compound – ladders, collections, a board that earns its own walls – this is your ruin, and a patient one. Anyone who wants the bonus all at once will find the sand runs deep here. For the builders among you, the Sphinx has kept something back.
Jungle Jim and the Lost Sphinx FAQs
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What is the RTP of Jungle Jim and the Lost Sphinx?
The RTP is 96.10%, rising to 96.30% if you activate the Win Booster. -
How volatile is Jungle Jim and the Lost Sphinx?
It’s a medium volatility slot, so wins tend to arrive at a steadier rhythm than in high volatility games, with the biggest payouts reserved for the free spins multiplier trail. -
How do you trigger free spins in Jungle Jim and the Lost Sphinx?
You need three or more scatter symbols, which can land on any reels without being adjacent. That awards 12 free spins on the expanded 5×5 grid with all 50 paylines enabled. Extra spins then come only from collecting Sphinx symbols, since scatters don’t appear during the round. -
What does the Sphinx symbol do?
It only lands on reel 3 during free spins. Each one is collected and removed, awarding an additional spin and raising the minimum multiplier on the trail. Even at the trail’s maximum, every appearance still adds a spin. -
Is the Win Booster worth using?
It improves your odds of triggering free spins by adding an extra scatter outside the reels and lifts the RTP to 96.30%, but activating it quadruples your total bet, since the per-spin bet multiplier rises from 10 to 40. -
What is the hit frequency of Jungle Jim and the Lost Sphinx?
The hit frequency is 30.55%, so roughly three spins in ten produce a winning combination. -
What is the maximum win on Jungle Jim and the Lost Sphinx?
The maximum win is 6,250x your bet. -
Who makes Jungle Jim and the Lost Sphinx?
Stormcraft Studios. Bets run from 0.10 to 80.00 per spin on a 5×4 grid that expands to 5×5.
