Highway to Bell: Stack & Collect

Highway to Bell: Stack & Collect is a Greentube slot released on September 22, 2026, running a rock-concert theme across a 5-reel, 4-row grid with 20 fixed win lines. Greentube rates its volatility at Level 4, high, and the Stack & Collect bonus caps out at a Grand Prize of 1,000x the total bet. An amplifier Wild substitutes for regular symbols and completes lines on its own, and Greentube has not published a public RTP figure for this title, gating that data behind operator login rather than the open game page.

Two optional side bets sit alongside the base game: Bonus Bet raises the odds of triggering the Stack & Collect round, and Inferno Bet boosts the value carried by Fireball symbols landing on the reels. Neither is required to play, and both scale with the current stake rather than being flat add-ons.

Bell Collect and Mystery Bell Collect

Fireball symbols land on the reels carrying their own cash value, and when a Bell Collector symbol appears alongside them, the bell tolls and gathers every visible Fireball value into one payout. A separate Mystery Bell Collect can trigger at random even without a Bell Collector present, sending Fireball values flying to a giant bell mounted outside the reel area for the same kind of collection.

Stack & Collect Bonus

Landing 3 Microphone symbols on reels 1, 3, and 5 opens the Stack & Collect bonus, which starts with 3 free spins that reset whenever a new Fireball or Incrementer symbol lands. Incrementer symbols add value to any Fireballs already visible before converting into one themselves, and filling an entire reel with Fireballs lets that reel’s bell toll up to 3 times, building a multiplier as high as 3x on that reel before it locks in place. Stacking enough locked reels is what pushes a round toward the 1,000x Grand Prize.

Highway to Bell: Stack & Collect Review

Highway to Bell: Stack & Collect layers three separate collection triggers, the standard Bell Collect, the random Mystery Bell Collect, and the reel-locking mechanic inside the bonus round, onto what is otherwise a straightforward 20-line rock-themed grid, and that layering is really the whole appeal. The Mystery Bell Collect in particular means a Bell Collector symbol missing from the reels does not shut the door on a collection entirely, which keeps the base game feeling live even between bonus triggers. Locking a reel’s multiplier at up to 3x once it fills with Fireballs gives the Stack & Collect round a visible sense of progress rather than a single blind pick, each locked reel is a permanent step toward the Grand Prize rather than a value that can be lost on a bad spin. The two optional side bets add a reasonable amount of control for players who want to lean into the Fireball-heavy build without committing to a full bonus buy structure, of which this game notably has none, everything runs through natural triggers and the two side bets instead. The absence of a published RTP is worth flagging directly since Greentube keeps that figure behind operator login rather than on its public game page, which is unusual for a modern release and means figures should be checked against your own operator before playing for real money.