Relax Gaming · 2026 · measured RTP 89.3% · tested 2026-11-03
Nuclear Tumble
Clearing every stone block sets off Meltdown in Nuclear Tumble, and the 136 Meltdowns of a 10,000-round demo test measured at 89.3% RTP paid more than its free spins did.
In numbers: the lab's RTP test on the official demo server measured 89.3% against 96.1% declared over 10,000 logged rounds; 20.5% of rounds paid; a natural bonus landed once per 303 rounds (33 in total) and a bonus round paid a median 36.7x the stake, mean 46.5x, trigger spin included; the biggest round paid 154.7x; the longest dry run was 28 spins.
Nuclear Tumble demo
United States·available at Cafe Casino
Same reels, real payouts
Cafe Casino runs the same Nuclear Tumble with the same math and adds a welcome bonus for players from the United States:
300% up to $2,000 + 150 FS 18+ · T&Cs apply · the demo stays free
Test card
10,000 spins · FUN 2.00 bet · every request logged
| Spins | 10,000 |
| Bet | FUN 2.00 |
| RTP declared | 96.10% |
| RTP measured | 89.27% (approximate 95% CI 78.5–100.1) |
| Hit frequency | 21% · every 4.88 |
| Dead streak max / avg | 28 / 4.9 |
| Median hit | 1.10x |
| Max win (no bonus round) | 126.7x · round 9345 |
| Free spins, natural | 33 · 3.3 bHz · every 303 spins · mean bonus round payout 46.5x stake |
| Balance start → end | 5,000 → 2,853 |
each run keeps its own spin log, CSV and raw server journal with checksums; the figures on this card combine all runs
Free spins on video
natural trigger · 33 in 10,000 spins
Three scatter canisters light up on the trigger spin and START takes 6 free spins at coin level 1 on a FUN 2.00 bet; collected caps raise the cap ladder four times as the bonus grows to 11 spins, the MELTDOWN sign lights up along the way, and TOTAL WIN counts up to 120.70 FUN. Recorded in a separate browser session, outside the statistical samples.
Across the whole run the 33 natural bonuses split into 7 under 20x, 18 between 20x and 50x, 5 between 50x and 100x and 3 at 100x or more, and together they made up 17% of everything the game returned. The wait between two triggers ran from 2 to 859 spins. Payout figures here cover the whole bonus round in ordinary stakes, the trigger spin included: its scatter pays and line wins count towards the bonus.
Nuclear Tumble free spins are never retriggered by scatters. Spins are added inside the bonus, one for every four caps collected together with a higher cap level, and one for each destroyed blocker that carries an extra spin. Leaving out the opening 6 or 8, the 33 natural bonuses gained 105 spins this way, at least one each, so they lasted from 7 to 16 spins.
- triggers 33 1 per 303 spins
- every 303 spins gaps 2 to 859
- mean 46.5x bonus round median 36.7x stake
- best 154.7x round 9567
- spins per bonus 9.5 7 to 16 observed
- 01round 956716 spins154.7x
- 02round 622912 spins135.3x
- 03round 83213 spins113.9x
- 04round 2549 spins80.9x
Risk profile
how much bankroll this run needed
| 50 bets | bust at spin 104 |
| 100 bets | bust at spin 771 |
| 200 bets | bust at spin 1485 |
One run, one bet size. A different session can bust earlier or never; treat this as a measured example, not a rule.
How it plays
33 rules screens from the game
Wins in Nuclear Tumble are counted as ways, 46,656 of them across six reels and six rows: three or more of a symbol on neighbouring reels, starting from reel 1, make a win, several matching symbols on one reel multiply the payout, and each symbol pays once, for its longest run. Six bears in caps pay 1x the bet, six tomatoes 0.6x, aubergines and apples 0.4x, blueberries 0.3x and each of the four card suits 0.2x. A Wild with a radiation sign can appear on any reel except the first and replaces every paying symbol. Paid symbols are cleared and the columns refill from above, again and again until nothing pays.
Each spin starts with up to 25 stone blocks on the grid. A win also breaks every block directly beside, above or below its symbols, and a broken block may reveal a cash prize symbol shaped like a bottle cap, an exploding bomb or one of three scatter symbols. A bomb waits until the cascade has run out of wins and then clears every non-cash symbol in its row and column. A cap pays its value, a multiple of the bet, only when it reaches the bottom row, smashing any block under it on the way down.
When the last block is gone and no win is left, Meltdown removes everything except the caps and drops a new grid with a better chance of more and bigger cash values. In free spins, bronze, silver and gold caps take their values from a coin level, from 1x to 5x for bronze at the lowest level up to 200x to 2,500x for gold at the top, and a round whose total reaches 5,000x stops there with 5,000x paid.
Collecting three scatters starts the free spins: plain ones give 6 spins at coin level 1, a Super scatter among them 8 spins at level 2 and an Ultra scatter 10 spins at level 3. A card then offers START, which keeps the award, or GAMBLE, a wheel that can move it up a level or lose it, repeatable until Ultra. Inside the bonus every four caps collected add a spin and lift cap values one level, and a destroyed blocker that carries an extra spin adds one more.
Build 1.0.3 rates ordinary play at 96.10%, the same as ENHANCED at 2x the bet with better feature chances, Golden Spins at 15x with gold caps only and Bonus Reels at 10x, which leave nothing but scatters and blanks on the reels. The rules and the demo configuration also list six buy modes with buying switched on, Free Spins at 50x, 100x and 200x for Normal, Super and Ultra and Golden versions at 400x, 750x and 1,500x, rated 96.50% like Meltdown Mode at 30x and Golden Meltdown at 175x, which jump straight to the Meltdown. This test played only ordinary FUN 2.00 spins, with no purchase, no ENHANCED and no S/C mode, within a bet range of FUN 0.20 to FUN 200.00 that applies to every mode.
Cascading reels
Wild symbol
Scatter symbol
Free spins
Gamble feature
Extra bet
Bet range FUN 0.20 – 200 per spin · payouts read from the game's paytable at bet FUN 2.00
Gallery
9 frames from the demo session
Verdict
Meltdown money from cleared blocks
Caps that reached the bottom row in the base game brought 9,342.0 FUN, 52.3% of the 17,853.1 FUN returned over 10,000 ordinary rounds at FUN 2.00, while ways wins made 5,933.7 FUN, 33.2%. Rounds 5314 and 1971 passed 100x on the back of one 100x gold cap each, in three and four cascade steps, and no larger cap was paid anywhere in the test, the best one inside free spins being worth 40x. Bigger ones showed up and paid nothing: gold caps from 200x to 1,000x stood on 71 base grids, and 70 of those rounds had no win at all, so the screen never cascaded and the cap never fell.
Spins were added inside every one of the 33 natural bonuses, and how far the cap values climbed shaped the payout. The three that stayed at coin level 1 averaged 15.47x the stake, while the four that reached level 5 averaged 120.78x, round 9567 among them at 154.65x, the best result of all 10,000 rounds. START was pressed every time, so 28 bonuses opened with 6 spins and five Super Free Spins rounds with 8.
Meltdown came in 136 of the 10,000 rounds, about one in 73.5, and every one of those rounds paid, at a median of 18.75x the stake. Together they returned 6,592.9 FUN, 36.9% of all payouts, and the 129 that started no free spins still made 35.2% of all payouts, against 17.2% for the 33 natural bonus rounds counted whole. Five of the eight largest rounds without free spins were Meltdowns, led by round 9345 at 126.7x.
- Meltdown paid in all 136 rounds where it fired, at a median of 18.75x the stake
- A Meltdown carried round 9345 to 126.7x with no free spins involved
- Round 9567 lifted the caps to coin level 5 and paid 154.65x, the best of all 10,000 rounds
- Each natural bonus gained spins after it began, 105 across the 33
- Gold caps of 200x to 1,000x sat on 71 base grids and not one was paid
- Base-game ways wins returned only 33.2% of all payouts over 10,000 rounds
- Three bonuses never left coin level 1, and the best of them reached 19.65x
- Ultra Free Spins did not come from any of the 33 natural triggers
Test record
10,000 rounds · 0 buys · open data · closed rig
One test run so far: a single session of the base game on the official demo server, every request and response logged; the game offers no bonus purchase, so every feature in the sample came from ordinary spins. When the game is tested again, the new run is added here and the figures on this page combine all runs into one sample.
- 10,000rounds logged
- 21%rounds that paid
- 155xbiggest round
- 1 / 303natural bonus rate
- 28longest dry streak
01run Run 012026-11-03 measured return89.27%-6.8 pts vs declared
- 95% band
- 78.5–100.1%
- rounds that paid
- 21%
- biggest round
- 155x · round 9,567
- longest dry streak
- 28
- natural bonuses
- 33 · one per 303 rounds
- balance start → end
- 5,000 → 2,853
- deepest drawdown
- 1,457x
10,000 ordinary rounds, including naturally triggered features, at a fixed FUN 2 bet; recorded on the official Relax Gaming demo server (jurisdiction MT, RTP profile 96.1%); every request and response logged; test run 2026-11-03.
The test rig plays the official demo build over the network and records every server round: bet, win, intermediate steps (cascades, respins), free spins, collect. Screenshots and video were captured in a separate browser session and are not part of the statistical samples. The text was read against the log by an editor before publication. How we test →
FAQ
6 questions · answered from the log
What triggers Meltdown in Nuclear Tumble, and how often does a base spin get there?
Meltdown starts when every stone block on the grid has been broken and the cascade has no win left; all symbols except cash caps are then cleared and a new grid falls. In 10,000 ordinary rounds at FUN 2.00 it came about once per 73.5 rounds, and those rounds averaged 24.24x the stake, the smallest at 0.20x.
Nuclear Tumble's RTP is 96.10%, so how did its demo come back at 89.27%?
The series staked 20,000 FUN and got 17,853.1 FUN back, 89.27%. Its approximate 95% CI, from 78.48% to 100.05% over those 10,000 rounds, contains 96.10%, so one series of this length does not pin the model down. Caps collected in the base game supplied 52.3% of all payouts and the free spins alone 14.4%.
Which bonus buys does Nuclear Tumble list, and which of them did the test use?
Build 1.0.3's rules describe a Buy Feature at 50x, 100x and 200x for Normal, Super and Ultra Free Spins and Golden versions at 400x, 750x and 1,500x, all rated 96.50%, and the demo's configuration lists the same six modes with buying enabled. None was used here, and all 33 bonuses came naturally from 10,000 ordinary FUN 2.00 spins.
Did the Nuclear Tumble test ever take the GAMBLE wheel before free spins?
No. In all 33 natural bonuses the test chose START, which plays the award as it lands: 6 spins at coin level 1 on 28 occasions and 8 Super Free Spins at level 2 on five. No trigger carried an Ultra scatter, so with no gamble Ultra Free Spins never started, and the bonus video shows the same START choice.
How do Nuclear Tumble free spins grow beyond six spins?
Inside the bonus, every four caps collected add one spin and raise cap values a level, and a destroyed blocker carrying an extra spin adds another. The 33 natural bonuses opened with 208 spins and played 313; round 9567, the longest at 16 spins, ended at coin level 5 and paid 154.65x.
How much can one bottle cap pay in the Nuclear Tumble base game?
In 10,000 ordinary rounds the largest cap ever paid was a 100x gold cap, 200.0 FUN at a FUN 2.00 bet, collected three times, in rounds 1971, 4649 and 5314. Gold caps worth 200x to 1,000x appeared on 71 grids but never reached the bottom row, 70 of them on spins without any win.
Comments and reviews
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- spins10,000
- bet2.00
- result-1,073x
- RTP measured89.3%
- bonuses33
- max win, no bonus126.7x
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