About This Slot
If you are familiar with Relax Gaming’s earlier Temple Tumble and it’s Megaways™ counterpart, both available at most casinos in our list of the best slot sites, then you will know what this slot is all about. Based amidst a kind-of Himalayan backdrop with one explorer gone missing and his equally gung-ho wife on the chase to find out what has happened to him, the action unfolds in Mayan-style temple with lots of weird looking masks and carvings building an eerie atmosphere. The surroundings also feature gold statues to the sides of the screen and skulls strewn on the ground. There are elements of many slots in here, even a hint of NetEnt’s famous Gozno’s Quest in some of the artwork.
The basic game is set on an 8×8 grid, but it includes some blocker tiles, which can be removed by hitting winning clusters, effectively opening up the opportunity for bigger cluters to form – like the grid slot equivalent of expanding reels if you like. Meanwhile, the Cluster Pays mechanic requires you to find at least 4 matching symbols in a group instead of matching symbols on a payline, and as usual, Cascading Reels give you many potential wins from one single spin.

RTP, Variance and Top Payout
Relax Gaming have become known for their extreme-variance slots, taking on the likes of Big Time Gaming and No Limit City to become the ultimate take no prisoners high risk maths kings. And Cluster Tumble is no exception – if you’re looking for relaxed gaming then you’re in the wrong place (excuse the pun) – this is anything but. The overall rating is a 5/5 on Relax’s own scale, so be prepared for a tough ride and uneven distribution of wins, though the minimum bet of 10p keeps the game playable for those with smaller bankrolls. The maximum payout of 20,000x stake is a tempting reward, just as one would expect to receive in exchange for a dangerous mission to the Himalayas…
As far as RTP goes, the base game setting for this slot is 96.4% but that figure can rise to 96.57% during the uber-volatile Free Spins round. And for those interested in the stats side of things, Relax also advertise the hit frequency of the game as 20.29% which means you hit a win roughly once every 5 spins.
Symbols and Graphics
As ever with Relax games, the artwork here is high quality and the production values are second to none. The symbols in Cluster Tumble are related to ancient Egypt and include colourful crystals, masks, scarab beetles and dragons. You could win up to 2,000x your bet for a cluster of dragon symbols, up to 100x your bet for clusters of scarabs or masks, and up to 50x your bet for clusters of crystals.
Meanwhile, Wild symbols can substitute for all other symbols in the game to form wins, while the fire and lightning symbols activate special features to boost your chances of creating clusters.

What We Like
Slick artwork and animations
Free Spins with Multipliers
Extra blocker tiles feature
High top payout
Random Wilds
What We Don't Like
Super-high volatility can be frustrating
Gameplay and Features
The name of the game here is to unlock the free spins round and free our hero explorer. There are various feature-tools at your disposal, including the classic grid slot Clusters and Cascades mechanics already mentioned, but also some nifty modifiers unlocked by landing adjacent clusters. Here is how it all works:
Cascading Symbols
When you hit a winning cluster of 4 or more identical icons, then the symbols will disappear to be replaced by a new set of symbols and more potential combinations. This gives you many winning chances from one single spin or cascade.
Cluster Pays
Instead of landing matching symbols on traditional paylines, you need to land at least 4 matching symbols in a cluster to receive a payout. The bigger the cluster of symbols, the higher the rewards. There are also blank ‘blocker tiles’ on the gird. If a winning cluster disappears next to them, then any of the following can occur:
Lightning Win
Tiles with a lightning symbol can transform into paying symbols when activated by a cluster. All symbols of this type give a win wherever they appear on the grid.
Fire Transform
Tiles with fire symbols can transform into a random paying symbol, with 1-2 other blocks becoming the same symbol in the next cascade.
Wilds
Wild symbols can substitute for all other symbols in the game. Tiles also have the potential to transform into Wilds at random if triggered by a winning cluster.
Free Spins
If you land 3 Scatter symbols or clear all the stone blocks, Free Spins will be activated. You will receive 5 Free Spins. If you clear all the blocks during Free Spins, you’ll get a 3x Multiplier and receive another 3 Free Spins. Another 3x Multiplier is awarded if you clear all the blocks again. Any Scatter landing during Free Spins awards an extra 1 Free Spin.
Our Verdict
Cluster Tumble is an enjoyable Mayan-themed slot with an evocative atmosphere, enhanced by the intro video and back story that introduces the action. The gameplay is interesting thanks to the Cluster Pays and Cascading Reels mechanics, which means you can get continuous winning streaks which unfold in smooth and dramatic fashion thanks to some superb animation by Relax’s production team. When the Multipliers are activated, this can also add up to give some serious winning potential. However, Cluster Tumble is clearly a highly volatile slot and it can be incredibly frustrating when clusters don’t quite land in the right place to trigger the blockers. So be ready for that maddening problem!
One of the best pulls of the game is the 20,000x stake top payout, which could be yours if the Multipliers go your way during Free Spins – and you really do need those Free Spins. In summary, this slot is fun for keen explorers but prepare for a tough adventure.
Good luck!
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