Venture deep into the jungle and start a quest for a hidden jackpot in Big Thunder, a 5 reel, 20 payline fixed jackpot slot from Ainsworth Technologies. Treasures lurking in the undergrowth here include a bonus feature that awards up to 30 free spins with potential 3x and 5x multipliers as well as a quartet of jackpot payouts. Play from between 30p and £3,000 per spin.

A lush, green rainforest is the setting for Big Thunder – joining the A to 9 playing cards are a bongo drum, a waterfall, a mask, a shield and a snake. 5 of the latter 2 award 5 times your total stake. The mighty gorilla is the game’s wild – it doesn’t offer any pays but replaces all other symbols apart from the scatter.

The Big Thunder logo is the scatter – landing 3, 4 or 5 of these anywhere on the reels will get you a payout of 2, 20 or 50 times your total stake. You’ll also trigger the Bonus Reel feature and be awarded 15 free spins.

These free spins are played on a new set of reels with all of the lower value playing card symbols removed. The paytable increases here too – the gorilla wild offers up to almost 70 times your total bet. The payouts from the other symbols rise too.

You’ll notice a 6th reel is in play during the feature – it contains 3x and 5x multipliers. If they land on a winning free spin, all of the payouts are boosted by the 3x or 5x multiplier. The scatter can also hit on reel 6. 6 scatters on the same spins pays 200 times your total bet. You can re-trigger more free spins here too with up to 30 in total possible.

Big Thunder also offers a quartet of jackpot prizes – in the base game, you’ll see a 6th bonus reel where a single symbol can land. If you hit a 5-of-a-kind combination and a matching symbol in the Bonus Reel window, you’ll trigger a jackpot. Whether you win the Mini, Minor, Major or Grand jackpot depends on the symbol and whether the combination contains a wild. This is known as the King Strike Bonus feature.

This is a pretty good slot from Ainsworth – the visuals are typical of a live casino game but work nicely. The base game action is solid enough with the 6th bonus reel adding an extra layer of intrigue. The game excels most in the feature round though.

The increased paytable plus the 3x and 5x multipliers make it well worth hitting. Add in the quartet of jackpots and this is a jungle trek well worth making. If you like jungle themed slots, Microgaming’s Jungle Jim is recommended.