Searching for an honest Big Thunder review before you commit real money? You're in the right place. Built by Ainsworth, it lands as a title with very high volatility and an RTP of 94.38%. It's built with crisp artwork and atmosphere and plays out on 5 reels and 15 paylines. The maximum win sits at 90,930x, so there's serious upside on the table. It first went live in 2017 and still earns its place today. So does it deliver? Let's get into it.
Written by Sarah Mitchell · Last updated: January 2026
Big Thunder is a slot from Ainsworth, given an engaging visual treatment. It runs on a 5-reel grid running 15 paylines with very high volatility, and a return-to-player rate of 94.38%.
The mechanics are what make Big Thunder interesting. Look out for scatter symbols that unlock free spins and extra bonus rounds. The very high volatility means patience is rewarded — expect quiet spells broken by bigger hits. All told, it's a serviceable entry in the Ainsworth catalogue.
The RTP of 94.38% is below the industry average of ~96%. This is common for older slots or those with special features. The lower RTP may be offset by unique mechanics or higher maximum win potential.
Very high volatility delivers the most extreme payout profile — long dry spells punctuated by potentially massive wins. Only recommended for experienced players with substantial bankrolls and high risk tolerance.
About 1 in 3 spins results in a win. This is a moderate hit frequency that balances win frequency with payout size.
Big Thunder features scatter symbols that can trigger free spins rounds. Landing the required number of scatter symbols anywhere on the reels activates the free spins feature, giving you extra chances to win without additional bets. During free spins, special modifiers may apply to boost your winning potential.
2.6 / 5 — Average
Big Thunder by Ainsworth provides a straightforward slot experience. While it may not break new ground, it offers very high volatility gameplay that will appeal to certain player preferences.