Susu & Koko Slot by Pragmatic Play

A locked row of six heart-shaped positions sits above the main grid. It opens left to right as tumbles chain within a single spin - one tumble unlocks the first position, three cumulative tumbles unlock the second, then six, nine, twelve, and fifteen for the rest. Reaching fifteen consecutive tumbles from one spin is rare in the base game, but each new position adds to the scatter pays count (8+ matching symbols anywhere on screen), which feeds more tumbles, which opens more positions. The loop is self-reinforcing once it gets moving.

Multiplier symbols ranging from 2x to 500x drop during spins and tumbles. In the base game they're additive and one-shot - a 50x and a 30x visible when the chain ends combine into 80x applied to your total sequence win, then they're gone. For 100x your bet you can buy straight into free spins, or toggle the ante at +25% cost for better scatter frequency (though that caps max win at 4,000x instead of 5,000x and locks out the buy option). Pastel pinks and soft yellows fill the background while Susu, the white bear, and Koko, the brown one, flank the reels alongside strawberry bowls, cakes, and smoothie cups - the whole thing looks like a dessert shop illustration, which makes the 500x multiplier ceiling feel slightly absurd by contrast.

Four scatters start 10 free spins, with 3+ scatters during the round adding 5 more. The locked row resets but cumulative tumbles across all spins count toward unlocking it, and once a position opens it stays open for the remainder of the round. Multipliers change entirely here - every multiplier symbol that lands adds to a running total that persists across every spin. A 20x on spin one, 15x on spin four, 100x on spin eight: spin nine applies 135x to all wins. That accumulation stacked on top of a progressively expanding grid is where the ante trade-off actually matters - longer free spin chains compound both mechanics simultaneously.