Series
Stack Em series
Stack Em series: from sticky wilds to competing bonus engines
Hacksaw Gaming's Stack Em line began with Stick Em in 2019, fixing cartoon presentation, persistent symbols and bonus-driven reel changes at the center of the family before later releases split into several formats. The foundation game uses a 5x4 layout, 1,024 ways and sticky wilds at medium volatility. What grew from it was not one repeated engine, but a loose mechanical workshop connected by the idea of symbols being held, stacked, collected or transformed.
Ranked by Slot Score
| Game | Year | RTP | Volatility | Slot Score |
|---|---|---|---|---|
 Stick EmHacksaw Gaming | 2019 | 96.1% | Medium volatility | 71 |
 Stack'emHacksaw Gaming | 2021 | 96.2% | High volatility | 83 |
 Stack'em ScratchHacksaw Gaming | 2022 | 60.12% | — | 35 |
 Canny the Can and the Book of TimeHacksaw Gaming | 2022 | 94.34% | High volatility | 69 |
 Keep ‘Em CoolHacksaw Gaming | 2023 | 94.07% | Medium volatility | 66 |
 Drop 'EmHacksaw Gaming | 2023 | 96.21% | High volatility | 82 |
 Keep ‘EmLatestHacksaw Gaming | 2024 | 94.25% | Medium volatility | 68 |
Stack'em produced the decisive upgrade in 2021. Its 5x6 cluster grid, high volatility, locking-win respins and increasing free-spin multipliers push the ceiling to 10,000x, while bonus buy changes how directly the feature can be reached. Stack'em Scratch then strips away the cascade loop entirely for a 3x3 scratch format with a fixed 0.1 stake and 10,000x maximum, showing how far the characters can travel from the founding reel game.
The recurring Em logic
- Cartoon code: exaggerated characters and compact visual jokes connect otherwise different themes.
- Symbol persistence: sticky wilds, locked wins, collections or hold mechanics make landed symbols matter beyond one evaluation.
- Bonus access: free spins and direct bonus options recur across the main slot branches.
- Format freedom: the family moves among ways, clusters, paylines, scratch play and hold-and-win rather than protecting one grid.
The later entries turn that freedom into separate mechanic lanes. Canny the Can and the Book of Time adopts a 5x3, 20-payline book structure with expanding symbols and random multipliers. Keep ‘Em Cool uses a 5x5 cluster grid and symbol collection at medium volatility. Drop 'Em expands to six reels and 7,776 ways, using cascades and symbol upgrades at high volatility, while Keep ‘Em moves to 15,625 ways with respins, hold-and-win and a cash collector.
Format changes that matter
- Stick Em: sticky wilds and 1,024 ways establish persistence as the starting idea.
- Stack'em: clusters, locking respins and increasing multipliers turn persistence into a high-volatility feature ladder.
- Canny the Can and the Book of Time: fixed paylines and expanding symbols redirect the family through a book-slot model.
- Drop 'Em: 7,776 ways and symbol upgrades shift the pressure toward cascades and stronger symbols.
- Keep ‘Em: hold-and-win and cash collection replace cluster building with locked-value accumulation.
Stack Em is less a strict sequel chain than a set of experiments around persistence. One game holds wilds, another locks winning positions, another upgrades falling symbols, and another collects cash values. The naming and cartoon tone provide continuity, but the meaningful comparison is which kind of carryover the player wants between evaluations or respins.