The diamond is the wild symbol, it will substitute for all of the other symbols, except for the scatter symbol, to help and form winning combinations.
The scatter symbol is some dynamite.
Every time that you land a winning combination, the Collapsing Reels feature is triggered. The symbols in that win will disappear to allow more symbols to fall from above. Hopefully this will form another winning combination and this way the process can continue indefinitely, allowing you to land multiple wins from a single spin.
The Diamond Drop feature begins when 2 or 3 scatter symbols land anywhere on the reels. Two scatter symbols trigger up to 2 reels and three scatter symbols triggers up to 3 reels. When a reel is triggered, numbers appear on every diamond above the reels and this shows how many multiplier wilds can collapse on that reel. If a win is formed on a triggered reel with diamonds stacked above it, then the reels collapse and up to three multiplier wilds will fall on to the reels. The multiplier wilds can be 2x, 3x or 5x, and if a win fails to land then the feature ends.
Cascading Cave offers a huge top payout of 2000x for landing five wild symbols or five miner symbols along a payline. The horse can payout up to 1000x, the lantern up to 500x, and the pickaxe up to 250x. The red gem can payout up to 100x, the green gem can payout up to 80x, and the blue gem can payout up to 50x.