Zombie Outbreak Slot by PG Soft

Green fluorescent lighting, a wrecked laboratory, and a female scientist clutching a pistol while the undead close in. The horror dressing is thick here - biohazard canisters, blood-splattered zombie silhouettes as premium symbols, and a color palette locked to toxic greens and steel grays. But the mechanic underneath the gore is surprisingly focused. Reels 2 and 4 are the only positions where Wilds appear, and when one lands it doesn't just substitute. It expands to fill the entire reel and reveals three stacked multipliers inside. Each winning cascade peels off the lowest multiplier, applies it to that win, and leaves the remaining values for the next drop. So a Wild showing x5, x10, x15 pays the first cascade at x5, the second at x10, and the third at x15 before it's spent. Two expanding Wilds on reels 2 and 4 simultaneously means two separate multiplier tracks running in parallel across the same cascade chain.

The multiplier set inside each Wild isn't fixed - it's drawn from five tiers ranging from x1/x2/x3 at the bottom to x10/x15/x25 at the top. Landing the highest tier on both Wilds during a long cascade sequence is where the 5,000x cap lives. Three scatters trigger 15 free spins (2 more per extra scatter, retriggerable), and the critical difference is that collected multipliers persist across all free spins instead of resetting each spin. A Wild that drops on spin 3 and gets partially drained still carries its remaining multiplier values into spin 4's cascade chain. You can buy directly into the bonus if scatter hunting on 1,600 ways feels slow. The collapsing reels clear winners after every hit and drop new symbols in from above, which is what keeps those Wild multiplier tracks feeding - without the cascade loop, a three-stage multiplier inside a single Wild would rarely pay more than once.