Pearl Harbor

How to Play

A 3×3 Inside a 7×7

Only the central 3×3 of the frame is live when a round starts, and a win needs five or more matching symbols joined by their sides within that area. Winning symbols clear, new ones drop, and the avalanches continue until nothing connects. Three things widen the area. An xBomb shifts or stretches it by a reel or a row, a Colossal symbol forces it open far enough to fit, and a Target lands anywhere in the 7×7, drags the edge out to include itself, and then turns Wild. A Target in a far corner can take the area from 9 cells to 25 in a single drop. Anything outside the live area counts for nothing, Scatters included, so the early expansions matter more than the small pays that come with them. The game adds any multipliers on symbols in a winning cluster to the round multiplier the xBombs have built, and that total multiplies the cluster’s pay. With the space-bar option ticked in settings, the keyboard starts each drop.

xBomb Wilds

An xBomb Wild clears up to 10 surrounding symbols, but never beyond the live area. Next to the border, it shifts the area by one reel or row; in a corner, it grows the area by a reel and a row together. Each explosion adds +1 to the multiplier for the next avalanche, or the (x) value the bomb was split into, and every xBomb detonates before the next drop. A split xBomb takes x2, then doubles again with each consecutive split. Scatters and converted Wilds outside a winning cluster survive the blast. The same bomb appears in Das xBoot 2wei, the studio’s later WWII submarine game.

RTP and Stakes

The default RTP is 96.21%, and the game also exists at 94.23% and 92.14%, so the figure in its rules screen is the one that applies to any given copy.

Nolimit City labels this game Extreme, while the stats row here calls it High. Both labels come from the same place. A round begins with nine live cells and needs five of them to match before anything pays, so many drops end with no cluster, and the value that does come waits on the area opening up or on a trip to the cockpit. The studio’s Extreme is the stronger reading of that pattern, and our High is the same warning on a coarser scale. The lightest round is €0.20 and the heaviest €100.

Cluster Payouts

Only the kamikaze pilot pays 1x for a five-cluster, and his ladder climbs to 625x for 40 or more. The admiral, fighter pilot, and sailor top out at 375x, 275x, and 180x, each equal to a rung one, two, and three steps lower on the pilot’s scale, and the five kanji plates finish between 75x and 30x. A 40-symbol cluster needs at least 40 live cells, so the last row only comes into play once the area reaches 7×6 or the full frame. A Wild can complete a cluster of any character or plate, though never a flag.

Detailed Review

Chaos With a Plan

The live area decides this game. Every other feature is judged by what it does to that 3×3 window. The xBomb matters because it moves the walls, a Target because it drags them out towards a corner, a Colossal pilot because the board has to make room for him. Even the xSplit, a feature the studio uses across its catalogue, reads differently here, since a split on a nine-cell board and a split on a 42-cell board are different events.

Most cluster slots hand over the full grid from the first drop and let the tumbles do the work. Pearl Harbor makes the grid the progression. A round has a shape, cramped at the start and wide open if the bombs and Targets cooperate, and that shape is what we’d point to as the studio’s cluster format at its most inventive.

The cockpit bonus keeps the same habit of building towards something. Three spins that reset whenever a multiplier lands, columns that launch Dogfight Attacks, and a full panel that calls in the Kamikaze wheel make it a multiplier puzzle rather than a run of free spins, and it looks nothing like the reels it replaces.

The cost is plain. Most drops pay nothing. Nine live cells and a five-symbol minimum leave very little room, and every round starts cramped again however far the last one got. The game is built to make that feel like progress anyway, because each bomb that moves a wall looks like a step forward even when no cluster follows, and long runs of small, dead rounds are the normal texture. Tora! Tora! Tora!, the mode with Midway Pop and Bomb Drop, is also the one a player meets least.

Per Lindheimer, the studio’s product owner, called the attack “perhaps one of the most chaotic events in history” at launch, and the board is built to that brief. Bombs clear holes, swords cut symbols in half, Colossal pilots shove the walls aside, and avalanches refill the gaps, all at once. It reads as noise for the first few rounds. Then, the order shows through, because each of those events answers the same question of how big the live area gets.

None of that undoes what the board achieves. The Border came first among the studio’s cluster games, but this is where the format found a plot, and few slots in this review series give a grid a reason to change shape. In the demo, the arc from nine cells to the full frame is worth watching more than once, and playing it free for a while makes it easy to count how rarely it completes.

It’s a cluster slot with a story, and the story stands up.

Frequently Asked Questions