Return to player
94.38%
Minimum bet
0.01
Game category
Video Slots
Variance
Medium
Reels
6
Progressive jackpot
Yes
Popularity
Maximum bet
3000
Game provider
Ainsworth
Bonus features
Yes
Paylines
30
Theme
Adventure
Big Thunder slot game online
Evan Carrington’s GCCans review describes Big Thunder as a well-designed 3D video slot in Ainsworth’s King Strike series. It targets players seeking action-focused play and flexible betting, offering free spins with multipliers and retriggers, stacked wilds, substantial scatter multipliers, and 4 jackpots. Since the game includes a 6th bonus reel, a jackpot can be triggered on any spin.
Theme and Story
Big Thunder belongs to Ainsworth’s ‘King Strike’ slot series. Its setting is a thick South East Asian jungle, with tigers and gorillas among Buddhist and Hindi relics. The imagery frames these objects as symbols of luck and fortune woven into the reels.
Graphics, Sound and Animation
Ainsworth gives the game a jungle backdrop populated by ancient relics and wildlife. The symbols use 3D artwork with crisp detail intended to remain clear on both mobile and desktop screens. The design is described as well suited to either device, with a chance to play for the progressive jackpot.
The audio also differs from the provider’s usual approach. Ainsworth often leans on classic slot sounds, leaving the action to carry the experience. In Big Thunder, the online slot game adds tiger and gorilla roars, along with thunder as an animated bolt strikes the reels ahead of a possible scatter bonus.
Top Casinos to Play Big Thunder:
How to Play
The opening screen presents several elements at once. Above the 5-reel layout sit the Major, Maxi, Minor and Mini progressive jackpots. A ‘Bonus Bet’ control appears on the right; it operates as a 6th reel and description, adds no extra cost to a spin.
To play for a jackpot, choose a wager per line and the number of lines through the menu or game interface. The line wager is multiplied by the selected lines to determine the total stake for each spin. Once the amount is set, spins can be started individually or through auto spins.
Reels 3, 4 and 5 can show the rare gorilla, which serves as the wild. It can stand in for any regular symbol to help form or extend a winning combination. Gorilla wilds may appear as stacks of 3 or as single symbols.
Regular symbols include an ancient religious mask, snake, shield, waterfalls, drums and the card ranks Ace, King, Queen, Jack, 10 and 9. The gorilla is also the top-paying symbol: combinations pay 2,000x, 300x, 100x or 5x the bet per line when 5, 4, 3 or hit an active pay line. Other regular symbols form paying combinations with 5, 4 or 3 matching symbols.
A scatter symbol awards multipliers on the total spin bet and can start the free spins feature, which the original review identifies as a source of many larger wins. The bonus reel’s ‘Kings Crown’ symbol is also needed alongside the pictured regular symbols to release a progressive jackpot.
Jackpots and Free Spins
Each jackpot depends on a specified combination landing on a pay line. In every case, the ‘crown’ must also land on the ‘Bonus Bet’ reel to activate the payout.
Major: 5 waterfalls, drums, shields, snakes or masks, plus the Crown on the bonus reel.
Maxi: 5 A, K, Q, J, 10 or 9 symbols, plus the Crown on the bonus reel.
Minor: 5 waterfalls, drums, shields, snakes or masks with the wild symbol, plus the Crown on the bonus reel.
Mini: A, K, Q, J, 10 or 9 with the wild symbol, plus the Crown on the bonus reel.
Landing the ‘Big Thunder’ logo scatter in any position across the reels can trigger free spins. The scatter first awards a multiplier of the spin bet based on the number shown. The listed values are 100x, 50x, 20x or 2x for 5, 4 or 3 scatters respectively.
The feature then awards 15 free spins on specially designed reels, with an added bonus reel showing x3 and x5 multipliers. Wins are multiplied by the symbol on that bonus reel. The Gorilla remains a substitute, while scatters can award a spin-bet multiplier and retrigger 5 free spins.
Bet Sizes, RTP and Variance
The source review describes a broad range of bet settings for Big Thunder. Its maximum is 30 lines at 100.00 per line, for a stated total of 3,000.00 per spin. The minimum is 1 line at 0.01 per spin. The listed RTP is 94.38%, and the game is classified as medium variance.
Review Summary
Big Thunder may appeal to players who enjoy free spins with multipliers and the possibility of a jackpot. The original review highlights the jungle theme, graphics and animation, noting how these elements work alongside the game’s features. It describes the overall play as lively, with several mechanics to explore.
With 12+ years of experience in the iGaming industry, Evan specializes in reviewing online casinos, analyzing slot games, and evaluating player safety. Their expertise covers casino licensing, RTP, volatility, bonus conditions, and withdrawal policies. Through hands-on testing and independent research, Evan delivers transparent, fact-based reviews to help players better understand gambling platforms, their features, and potential risks.
