Only Coins Express Slot by Gamzix

No paylines. No regular symbols. No fruit, no card royals, nothing that pays in combinations. The entire game runs on coins landing on a 3x3 grid against a nighttime railway backdrop - dark purple-blue sky, iron trestle bridge silhouette, and a golden steam locomotive perched above the reels like it's about to roll right through them. Three coins filling the middle row trigger the bonus round, and a random Heap of Coins feature forces the trigger on any spin where at least one coin appears. Coins carry values between 1x and 9x, but the interesting symbols are the ones that don't show their hand immediately. Sticky Mystery symbols lock in place during the base game, sitting there through normal spins without revealing anything, then crack open when the bonus starts to show either a coin value (1x-9x) or a jackpot tier.

Four jackpots - Mini at 10x, Minor at 20x, Major at 50x, Grand at 500x - displayed in stacked meters along the left edge in blue, green, purple, and red. The bonus plays as respins where only coins, jackpot coins, and two special types appear. The Collect symbol sweeps across the grid left to right, top to bottom, gathering every visible coin value into one payout. For 50x, the buy bonus drops you straight into the respins without waiting for three middle-row coins to line up naturally.

The Walking Multiplier is a golden frame that doubles whatever sits in its position. It moves across the grid between respins, landing on a new spot each time. When it overlaps a coin, that coin pays double. But the interaction with Collect is where it gets specific: if a Walking Multiplier occupies the same position as a Collect symbol on the same respin, the entire Collect payout doubles. Not just the coin underneath the frame - everything the Collect swept up. On a grid this small, the symbols are dense enough that a well-timed Collect with the multiplier active is the realistic path to the 2,000x ceiling rather than stacking individual coin values across nine positions.