Monster Pop

Monster Pop is a cluster-pays slot from Betsoft that starts you on a 5x5 grid and lets it grow up to 13x13 as you play. Released in March 2020, it ditches traditional paylines entirely in favour of clusters, where matching monsters grouped together anywhere on the grid count as a win. The expanding grid mechanic is what makes this one stand out from the crowd, and once the reels start growing, the game feels genuinely different from anything else in Betsoft's catalogue.

The whole thing is wrapped in a colourful monster theme with cartoon creatures living inside a cave. It looks playful rather than scary, and the animations are smooth enough to keep sessions entertaining without slowing the game down.

How Cluster Pays Work in Monster Pop

Forget paylines. In Monster Pop, you win by landing clusters of four or more identical monster symbols touching horizontally or vertically on the grid. The bigger the cluster, the bigger the payout. Clusters of four monsters pay the smallest amount, while the game technically supports clusters of up to 1,000 symbols on a fully expanded grid, though you will rarely see anything close to that number.

After a winning cluster forms, those symbols disappear and new ones drop in from above, similar to cascading reels in other slots. This chain reaction can lead to multiple wins from a single spin, especially when the grid has already expanded.

Monster Cloner and Grid Expansion

The Monster Cloner is the signature feature here. When this special symbol lands on the grid, it duplicates a neighbouring row, column, or both, pushing the grid beyond its default 5x5 size. Each Cloner adds one expansion, and because Cloners can appear on consecutive spins, the grid can keep growing until it hits the 13x13 ceiling.

In the base game, the grid shrinks back down after a non-winning spin, so expansion is temporary unless you keep winning. During free spins, though, the grid stays expanded regardless of whether you hit a cluster or not. That persistence is what makes the free spins round significantly more valuable than the base game.

As the grid expands, Oracle Eye wild symbols are added to the reels. These wilds substitute for any monster symbol but cannot replace the Monster Cloner or the Flaming Sphere scatter. More grid space means more wilds, which means bigger clusters become much more likely on an expanded board.

Monster Fury Feature

Monster Fury is a random rescue mechanic that can trigger after any non-winning spin. When the monsters get agitated, one of two things happens. Either a Cloner Bomb goes off and scatters Monster Cloner symbols across the grid, forcing an expansion on the next spin, or the monsters reshuffle their positions on the grid, grouping identical symbols together to form clusters that were not there before.

You cannot trigger Monster Fury on demand, and it does not appear on every losing spin. But when it does fire, it can turn an empty spin into a decent win, particularly if the Cloner Bomb version activates and expands the grid before new symbols drop in.

Flaming Sphere Free Spins

Landing three or more Flaming Sphere scatter symbols anywhere on the grid triggers the free spins round. Three scatters award seven free spins, with one extra spin added for each additional scatter beyond three. The maximum is 17 free spins if enough scatters land at once, though getting more than seven or eight is uncommon.

The critical difference during free spins is that the grid does not contract after losing spins. Any expansion from Monster Cloner symbols sticks for the entire round, so the grid tends to grow larger with each spin. By the end of a decent free spins session, you could be playing on a grid far bigger than the base 5x5, with wilds scattered throughout.

Free spins can also be retriggered if additional Flaming Spheres land during the round, adding more spins to whatever you have left.

Betting Range and Payouts

Stakes run from £0.25 to £25 per spin, which keeps Monster Pop accessible for casual players while still offering enough range for mid-stakes sessions. There is no bonus buy option and no gamble feature.

The maximum win sits at 2,270x your total bet, which is respectable for a game with this volatility profile. Most of your wins will come from smaller clusters in the base game, but the free spins round is where the larger payouts tend to appear, thanks to the persistent grid expansion and additional wilds.

All eight monster symbols pay the same values, so the game is more about cluster size than landing specific high-value symbols. This keeps the maths straightforward and means every monster on the grid has equal potential.

Playing on Mobile

Monster Pop is built in HTML5 and works across all devices through the browser. The expanding grid translates well to smaller screens since the game adjusts its zoom level as the grid grows. All features, including Monster Fury and grid expansion, work identically whether you are on a desktop, tablet or phone.

How Monster Pop Compares

If you enjoy cluster-pays mechanics, Monster Pop sits alongside games like Reactoonz and Sweet Bonanza in terms of its core concept, though each takes the idea in a different direction. Reactoonz uses a fixed 7x7 grid with cascading features, while Monster Pop's expanding grid gives it a more dynamic feel as each session unfolds differently depending on when Cloners appear. Fellow Betsoft title The Hive shares the same low-volatility approach but uses a hexagonal honeycomb layout instead.

For players who want a slot that rewards patience and builds momentum over a session rather than relying on a single lucky spin, Monster Pop is a solid choice. The 97.07% RTP is well above average, the cluster mechanic is easy to follow, and the expanding grid adds a layer of anticipation that traditional reel slots cannot match.