Millionaire Mystery Box Slot Review

Almost a year after the release of Who Wants to Be a Millionaire in November 2018, Big Time Gaming prepares the second slot on this theme. The sequel is planned for November 6, 2019, and offers a massive top reward during free spins. Check what is new and different in the review here.

Millionaire Mystery Box Overview

Millionaire Mystery Box

Big Time Gaming decided to use the 243 ways to win system for the second part of the game inspired by the popular quiz. It lacks the cascading system, the extra bottom horizontal reel, and the Megaways mechanics. Instead, the second version has a mystery box feature and a wild with x2 win multiplier. The latter multiply each other when you land more than 1 in a spin. Also, the free spins you will play with a win multiplier that can reach up to 50x.

Available on:






Game Type:

Video Slot

Millionaire Mystery Box Details

  • Bonus Game:
  • Yes
  • Rating:
  • 9.26
  • Progressive:
  • No
  • Paylines:
  • 243
  • Wild Symbol:
  • Yes
  • Reels:
  • 5
  • Scatter Symbol:
  • Yes
  • Autoplay Option:
  • Yes
  • Multiplier:
  • Yes
  • Min Coins Size:
  • 0.20
  • Free Spins:
  • Yes
  • Max Coins Size:
  • 100
  • Jackpot:
  • 1.200.000

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About Millionaire Mystery Box Slot

Millionaire Mystery Box is a video slot with 5 reels, 3 rows, and 243 ways to win. You will get paid for every 3 to 5 matching symbols arranged from left to right on adjacent reels. You can use wagers from 0.20 to 100 credits per spin on this medium volatility game with a return to player rate of 96.64%. Players can take advantage of a Mystery Box Reveal feature. It can uncover any symbols including wilds and scatters.

Like in the original slot, the highest cash prizes are in the Hot Seat. There you can win from 7 to 20 free spins initially and up to 17 more free spins in the feature. You will play them with a starting multiplier of x2 increasing its value to reach up to 50x. The top cash prize you can score in the video slot is impressive – 12,000 times your stake. This makes £1,200,000 for those playing with the highest bet size.

Millionaire Mystery Box Design

As a background for the well-known game is used the stage of the worldwide popular TV show. You will see the familiar lighting and hear playing the popular song of the game unchanged. The same neon scene and the hot seat are placed behind the transparent reel grid. BGT kept unchanged the same symbols from its first game to appear in the centre of the window. These are the card royals from 9 to A and the gems in red, blue, green, and purple.

There is a colourful x2 wild symbol, a mystery box symbols, and the game logo scatter. Spotlights like these in the game show will illuminate your screen. The soundtrack is identical to the original game show. It will highlight certain moments and synchronise to the action of your gameplay. Millionaire Mystery Box is a slot with medium volatility and an RTP of 96.64%.

Millionaire Mystery Box Gameplay

The 9 to A card royals are at the low end. Next in value are blue, red, green, and purple gems, the latter of which is the top paying symbol. Landing 5 purple gems on adjacent positions give you 25x your stake. The rainbow-coloured 2x symbol is the wild and it appears on reels 2, 3, and 4 only. It doubles all your wins and multiplies its value if you land more than one wilds on a winning combination. Thus, one wild gives an x2 boost, two wilds – 4x, and 3 wilds – 8x boosts. Normally, this symbol substitutes the regular missing ones.

There is a mystery box symbol- a question mark which just like the wild you can see landing on the middle 3 reels only. The scatter is the game logo with 3 of it activating the free spins. The features active during the base game are the Multiplier Wild, explained above and the Mystery Box symbol. When you land a mystery box, all instances of it transform into any random symbol. This includes the wild and the scatter. This way it helps you get more winning combinations and activate the free spins.

Millionaire Mystery Box Features & Bonuses

BGT included a Gamble feature which is a part of the original TV quiz’s rules as well. You can use it after every winning combination during the base game. This feature lets you take your chance with 50:50 risk to double up your payouts or lose them. You have the opportunity to go on gambling your wins doubling them step by step until you reach the roof. Or you can decide to collect your winnings.

In the first version of the game, you can win up to 50 free spins through gambling. Unlike it, in Millionaire Mystery Box you need to land at least 3 scatters to get access to the Free Spins. The starting level and the multiplier value you will begin the rounds with depend on the number of the triggering scatters as follows:

  • 3 triggering scatters = Level 1 – 7 free spins with a starting multiplier of x2
  • 4 triggering scatters = Level 2 – 12 free spins with a starting multiplier of x3
  • 5 triggering scatters = Level 3 – 20 free spins with a starting multiplier of x4

On the left of the reels, you will spot a ladder set containing extra spins and multipliers. Every additional scatter you land during free spins will advance you up on the ladder as follows:

  • the 1st scatter increases the multiplier to x3 and awards 1 more free spin
  • the 2nd scatter increases the multiplier to x4 and awards 1 more free spin
  • the 3rd scatter increases the multiplier to x5 and awards 3 more free spins
  • the 4th scatter increases the multiplier to x6 and awards 1 more free spin
  • the 5th scatter increases the multiplier to x7 and awards 1 more free spin
  • the 6th scatter increases the multiplier to x8 and awards 1 more free spin
  • the 7th scatter increases the multiplier to x9 and awards 3 more free spins
  • the 8th scatter increases the multiplier to x12 and awards 1 more free spin
  • the 9th scatter increases the multiplier to x15 and awards 1 more free spin
  • the 10th scatter increases the multiplier to x30 and awards 1 more free spin
  • the 11th scatter increases the multiplier to x50 and awards 3 more free spins

After you reach the highest multiplier value, you will receive +1 free spin for each scatter you land. This will go on until the feature comes to an end. The win potential here is massive – 12,000 times your stake.

The Conclusion

Millionaire Mystery Box has new features and innovations. They will certainly find fans among the successful TV quiz. Unlike the first Megaways version, here the volatility is medium and the RTP is higher. Also, the free spins you will play under different rules. The win potential is more than attractive – 12,000x stake. If you like Big Time Gaming’s first version, you must try the second one!

Millionaire Mystery Box Theme

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Casino review by


Date: 7 November,2019

Hey there, I'm George, an old-school slots enthusiast and gambling expert. I've been passionate about slots, poker, and online casinos for years, and I love sharing my knowledge with others. Whether you're a seasoned player or just starting out, I'm here to help you with any gambling-related questions you may have. So, feel free to reach out to me anytime!