Developer 
Lines RAINBOW STACKS™ by Revolver Gaming is a five-reel, 25-payline slot with medium volatility and an Irish-themed presentation. The game combines a Wild symbol, high-value and low-value symbols, treasure pots and a paying scatter, with bonus features built around the rainbow and leprechaun theme.
The demo version allows players to play for free and practice before playing for real money. The Jackpot Bonus begins when black pots land on the first and third reels, with the fifth reel revealing one of four pot types tied to a progressive prize. In the bonus round, Lucky the Leprechaun provides three chances to reveal prize pots, which stack until the jackpot meter is reached.
Three Large Coin Scatter symbols on reels two, three and four activate eight Free Spins, with extra free games awarded by additional scatters during the round. If the required pot combination appears during Free Spins, a version of the Jackpot Bonus can also trigger, adding another layer to the slot's main game mechanics.
