The game's logo is the wild symbol and it can substitute for all the other symbols, except the scatter, to help and form winning combinations.
The shield is the scatter symbol and it is the key to the game's bonus feature.
When the shield scatter symbol lands on reels one, three and five simultaneously the Jungle Trail Free Spins begin. There are four different free spins levels that are unlocked the more times you trigger the game. The first trigger offers the Deep Jungle, this is eight free spins with a 5x multiplier and an Ultra Spin. The Ultra Spin is an extra final spin worth up to 25x the prize. From the fifth trigger you can play Crystal Falls, ten free spins with up to four wild stacks on each spin. From the tenth trigger you can play The Golden Mountain, fifteen free spins with wilds that stay on the reels and nudge up or down on each spin. From the fifteenth trigger you can play The Lost City of Zantar, twenty-five free spins with a wild that shifts horizontally and increases the multiplier.
The free spins continue to improve the more you play. From the twentieth, twenty-fifth, thirtieth and thirty-fifth trigger each spin mode receives a payment boost that increases the number of free spins.
As an added extra, the slot has a number of achievements that you can unlock. Each time you achieve one you will receive a notification and can check them in the paytable.
Heart of the Jungle has a top payout of 2,000x for landing five wilds across the reels. The male character can payout up to 500x, the female up to 200x, the chimpanzee up to 100x, the elephant up to 50x, the leopard up to 40x and the parrot up to 30x.