Mega Deep Slot by Genii

The cabinet sits inside a rusted oxygen-pipe ring, barnacle-crusted at the joints with orange coral colonies blooming at each corner, and the reels hover in a navy canyon where vertical cliffs squeeze in from both sides. Light filters down from somewhere far above. The royals are driftwood letters wrapped in fishing net (yellow A, red K, purple Q, green J), and the high-pays are a teal deep-sea anglerfish dangling its glowing pearl lure and a red-orange hermit crab planted on a sandy reef. The shark Wild has a green "WILD" plate stamped across its belly.

Two scatter symbols, and they do completely different jobs. The diver portrait, scuba helmet on and red "FREE SPINS" lettering across his chest, only lands on reels 1, 3 and 5 in the base game. Three of him pays out a flat 8 free spins. No 4-of-a-kind, no 5-of-a-kind, no scaling award, because the reel placement makes those combinations impossible by design.

Once the bonus starts, the diver disappears entirely. He doesn't retrigger. Instead a second scatter takes over reels 1 and 5, and two of those add 3 spins to the counter. That's the only way to extend the round, and you can stack the +3 awards across multiple pairs.

The bonus itself is the whole reason the game exists, and it's the same engine running through Genii's Mega Reel sub-line (Mega Cats, Eagle Eye, Golden Wolf). Reels 2, 3 and 4 fuse into a single 3-wide block. After every spin, whatever symbol lands in the centre of reel 3 expands to fill all nine positions across that block. Every free spin, guaranteed. So if the centre lands on the anglerfish, you've got a synced 3-reel hit on every payline that touches the middle row, before the outer reels are even evaluated. A mid-pay symbol doing this is what the math is built around. The high-pay version is where the 62,500-coin ceiling lives.

No buy bonus, no ante, no jackpot ladder. The 25 lines play at one of five chip sizes from a penny to fifty cents, multiplied by five coins per line. One trigger, one mechanic, and the deep-sea trim around it.