io

Six columns and four rows drop 24 symbols into play on every spin for IO, the second Elk Studios release built on the studio's Gravity engine, and this time the setting shifts to a mining outpost orbiting Jupiter's volcanic moon of the same name. Wins form from three or more matching icons landing consecutively from the leftmost column outward, and the base grid already produces 4,096 ways to win from a paytable of round-disc royals (J through A), stars, clovers, diamonds and a top-paying lucky seven worth 5x a bet for six across the reels.

Every winning combination is cleared under the Avalanche system, and rather than dropping straight down, replacement symbols slide diagonally left or right to fill the gaps — a quirk of the columns not sitting flush against each other. Each avalanche also adds a row to the grid, up to a ceiling of eight, at which point the ways total balloons to 262,144. Chains of consecutive avalanches are common, since one avalanche's gaps can immediately set up the next.

Three wild types work the reels. A standard wild fills in for the paytable, a Charged Wild starts with four lives and loses one every time it contributes to a win before disappearing once they're spent, and a Wild Forge drops a multiplier wild into the space directly beneath it whenever it appears, with that multiplier's value climbing every time the Forge triggers again and no ceiling on how high it can go — if a Forge symbol ever reaches the bottom row, it turns into a wild multiplier itself.

A laser symbol fires a beam that wipes out itself and every regular symbol it passes through, opening space for the avalanche to refill; when two beams cross, everything along both paths up to that crossing point converts to wild. Landing three or more bonus symbols opens the free drops round, awarding at least seven drops and as many as fifteen for six bonus symbols in view, with retriggers possible during the round itself. The grid locks at its full eight-row size for the whole bonus, and whichever Charged Wilds or Forge symbols are already in play stay pinned along the bottom row instead of resetting between drops.

RTP is set at 96% against 8/10 volatility, hit frequency runs at 24.6%, and the ceiling on offer is 5,000x for a bet between 0.20 and 100. The pace leans on those chained avalanches for its rhythm — regular small hits keep the grid moving, while the free drops round, stacked with sticky specials carried over from the base game, is where the multiplier engine really gets to build.