Who Wants To Be A Millionaire Mystery Box

By Matthew Kennedy | Updated 10 June 2026

Big Time Gaming has released Who wants to be a Millionaire Mystery Box which is the sequel to Who wants to be a Millionaire which is based on a popular game show. Features are multipliers, free spins and a Mystery Games box.

About the slot

Who wants to be a Millionaire Mystery Box is a 5 reel video slot with 243 ways to win. You can spin the reels from 20p to £100 per go and it can be played across all devices.The transparent reels are set on the background of the game show, and symbols are the  9 to the Ace royals, green, blue, red and purple gems the latter having the highest value , 5 on a payline will give you x25 of your wager.The wild symbol comes with a x2 multiplier, and it can only appear on reels 2-4, if you land more than one wild on any single spin the values will be multiplied. The scatter symbol is the Millionaire logo.

Gameplay

The Mystery Box Reveal feature can be triggered randomly and can reveal any of the games symbols.After a winning combination, you will be given the choice to gamble your winnings up to 5 times, but watch out, it is all or nothing.Landing 3 or more of the scatter symbols will trigger the free spins feature and you will be awarded with 7 bonus spins, on the left of the reels you will see a multiplier ladder and each scatter that lands on the reels will move you up the ladder where you can also earn bonus spins.The ladder has 12 rungs and each rung will award you with 1 bonus spin and increasing multiplier, except for rungs 4, 8 and 12 where you will receive 3 bonus spins, the maximum multiplier you can get is x50.This was such a fun game to play, nice graphics and animations and the original games soundtrack makes you feel like you are actually taking part. You can pocket up to 12,000 of your wager in the free spins feature with the maximum multiplier. The RTP is 96.64%.

Matthew Kennedy

Co-founder & Technical Director at Play Cash Games

Matthew Kennedy co-founded Take Marketing Limited in 2008 alongside Becky Mosley and has worked in the UK online gambling industry ever since. He runs the technical side of the operation, building and maintaining the platforms that power Play Cash Games and the wider Take Marketing portfolio.

Matt's role is hands-on. He writes the code behind the offer feeds, the comparison tools readers use, and the back-office systems that keep every casino listing accurate and current. If you have used a feature on this site, the chances are he built it. He is also responsible for site performance, mobile usability, and the technical SEO that lets a small independent comparison site compete with much larger publishers.

Over 17 years in the industry, Matt has worked directly with affiliate platforms, casino operators, and software providers. He has seen the market move from desktop Flash slots to mobile-first HTML5, lived through every iteration of UK Gambling Commission rules, and built the systems that keep our coverage compliant as regulation evolves. He has a particular interest in responsible gambling tooling and player-fund safety — the parts of the industry most people do not see but that matter most.

Matt is a Companies House registered director (Take Marketing Limited, company no. 07619813) and is based in Lincolnshire, England.

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