Cave of Gems by BF GAMES is a 5-reel, 3-row slot with 30 paylines and high volatility. Winning combinations are formed from left to right, with only the highest win on each payline counting. The game carries an RTP of 94.09% and allows bets from 0.3 to 90.
The main mechanics centre on Nitro symbols and Persistent Wilds. Nitro symbols can land as singles, doubles, or triples, increasing a counter on the reel; when that counter reaches three, the reel becomes a Persistent Wild for the next three spins. If all five reels turn Persistent Wild at once, the game awards 200x the bet. The Treasure Chest scatter can appear on any reel and trigger 10, 15, or 20 free games from three, four, or five scatters.
During the free games round, a Grand Nitro Meter tracks Nitro symbols and can lead to a 500x bet reward at 15. If the meter reaches at least three, the Explode Feature may add Bomb Wild symbols to random reel positions before resetting the meter. A demo version is available to play for free, giving players a way to practice before playing for real money.