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Millionaire Mystery Box Slot Review

Millionaire Mystery Box is an online slot with 96.24 % RTP and medium volatility. The game is provided by Big Time Gaming; the software behind online slots such as Temple Quest, Temple of Fortune, and Survivor Megaways.

Screenshot of the Millionaire Mystery Box slot by Big Time Gaming

Millionaire Mystery Box Details

Millionaire Mystery Box is a real money slot with a TV Shows & Movies theme and features such as Wild Symbol and Scatter Symbol. Here are some more facts about Millionaire Mystery Box.

Feature Detail
Software Big Time Gaming
RTP 96.24 %
Paylines 243
Bet range $0.2 – $100

Medium Volatility


Millionaire Mystery Box is an online slot with medium volatility. It means that the number of times you win and the amounts are in balance.

Rated 4.5 / 5 points
By players

Millionaire Mystery Box Casinos

Play $20, Get 50 Free Spins
and claim up to $50 Bonus
18+. Full T&Cs apply. New players only. Min deposit £20. 40x wagering applies to match up bonus. Offer valid for 1 week. 50 Spins on Starburst. 40x wagering applies to Spins.
Play $10, Get 108 Free Spins
and claim up to $200 Bonus
First Deposit Only. Min. deposit: £10. Game: Spinning Wilds, Spin Value: £0.1, Max Free Spins: 108. WR 60x free spin winnings amount (only Slots count) within 30 days. Max bet is 10% (min £0.10) of the free spin winnings amount or £5 (lowest amount applies). Free Spins must be used before deposited funds. Deposit/Welcome Bonus can only be claimed once every 72 hours across all Casinos.
25 Spins on Book of Dead
and claim a $25 Welcome Bonus
Automatically credited upon deposit. Cancellation can be requested. First Deposit Only. Max. Bonus £25. Maximum amount of Free Spins is 25. Game: Book of Dead, Spin Value: £0.10. WR of 30x Deposit + Bonus amount and 60x Free Spin winnings amount (only Slots count) within 30 days. Max bet is 10% (min £0.10) of the free spin winnings and bonus amount or £5 (lowest amount applies). Spins must be used and/or Bonus must be claimed before using deposited funds. Deposit/Welcome Bonus can only be claimed once every 72 hours across all Casinos

Millionaire Mystery Box RTP

The Millionaire Mystery Box RTP is 96.24 %, which makes it a slot with an average return to player rate. For a better return, check out our page on high RTP slots.

RTP stands for Return to Player and describes the percentage of all wagered money an online slot returns to its players over time.

For example, a slot machine like Millionaire Mystery Box with 96.24 % RTP pays back 96.24 cent for every $1. Since this is not evenly distributed across all players, it gives you the chance to win high cash amounts and jackpots on even small deposits.

Features Overview

Millionaire Mystery Box is a 243-payline slot with Wild Symbol and the chance to win free spins in-play. Below is a table of more features and their availability on Millionaire Mystery Box.

Feature Available
Wild Symbol
Scatter Symbol
Free Spins
Bonus Games
Progressive Jackpot

Who Wants to be A Millionaire Mystery Box Review

The 2019 release of the Who Wants to be a Millionaire Mystery Box slot game from Big Time Gaming is coming out hot on the heels of their similarly titled release from 2018 with the popular Megaways feature. The popularity of the original made it easy to push ahead with another installation of the Millionaire franchise. This successful game show has the aesthetics and suspense we all look for in an online slot. BTG’s Millionaire Mystery Box slot represents the show in a fun new way and comes with hot features you are likely to enjoy. The main feature is the mystery box symbol with exciting gifts on the reels. Will the mystery box create a payline win of matching symbols? Only one way to know. Don’t be shy; let’s open these boxes together!

Who Wants to be a Millionaire Mystery Box Free Spins

The free spins are the big draw to this game. The scatter symbols are represented by the ‘Who Wants To Be A Millionaire’ logo, and hitting 3, 4, or 5 of them will provide you with 7, 12, or 20 free spins. Connecting to well-known prize levels of the game show, the free spins also increase the excitement with every step higher that you go.

Starting at the lowest win multiplier of 2x, you can move up to the top 12th step to reach the amazing 50x multiplier. Every scatter that lands during the free spins feature adds to your ladder rung position, increasing the win multiplier and providing an extra free spin. On steps 4, 8, and 12, you get an additional three spins. Once you reach the top, every subsequent scatter adds on 1 free spin. The gamification of extra spins and multipliers connects fantastically with the show and makes this the best free spins offer of any slot game.

More Features & Wager Limits

The Who Wants to be a Millionaire Mystery Box slot has, of course, the eponymous mystery box that is a blue box with a large yellow question mark and opens to reveal a symbol. All mystery boxes on the reels will open with the same symbol – even wilds can appear! We think this feature doesn’t add that much to the game in terms of wins or excitement. The reels could simply show the expected symbols themselves; no need for an additional animation to open the boxes and see if we won. A progressive box counter would have been a nice touch to this feature where, for example, you could get a big multiplier after every 20th box. As it is, we find it to be underwhelming, but others might really like it. We fully accept that our unfavourable opinion of the mystery box could be based entirely on our impatience to get to another free spins feature. Come on, let’s go, free spins! Let’s goooooo!

Additional features include wilds that provide a 2x win multiplier and a gamble feature after every regular game win. The doubling wilds seem to land generously during our gameplay, where 2 or 3 of them string together a nice win multiplier on many paylines. The gamble feature is similar to other game provider offerings, for instance, from Amatic and Novoline. In this slot, the gamble option allows you to double your win total up to 5 times, meaning a $3 win can potentially grow to $96.

There are 243 win lines on this 3×5 slot reel design, as well as medium volatility. Bet sizes offered range from $0.20 to $100, and the maximum payout is 12,000x your bet.

Millionaire Mystery Box Slot Design & Music

We really enjoy the Millionaire game show franchise, and every element of the studio audience, the hot seat, and suspenseful music has been successfully incorporated into this slot game. The Mystery Box edition is a classical style of slot game for the Millionaire players that accompanies 2018’s Megaways offer very well.

Review Summary

Who Wants to be a Millionaire Mystery Box is a fun game with all the music and suspense of the game show baked right into the design, atmosphere, and features of this slot. While it is still a mystery to us why they included the box feature, we love the ladder rungs during the free spins. That is truly where this game shines and can go wild with big multiplier wins. If you like the Millionaire game show and are a fan of free spin features, spend some time with this fabulous slot game.

Millionaire Mystery Box on Youtube

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What is the Millionaire Mystery Box RTP?

Millionaire Mystery Box returns 96.24 % for every $1 wagered back to its players.

What are the key features on Millionaire Mystery Box?

The online slot features Wild Symbol, Scatter Symbol, Free Spins, and Multiplier.

What is the number of paylines and reels?

Millionaire Mystery Box features 243 paylines across 5 reels.

What is the Millionaire Mystery Box volatility?

Millionaire Mystery Box is an online slot with medium volatility.

Who is the maker of Millionaire Mystery Box?

The slot game Millionaire Mystery Box is brought to you by Big Time Gaming.

All Big Time Gaming Slots

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Temple of Fortune 94.9 % Medium
Survivor Megaways 96.47 % High
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Dragon Born 95 % Medium
Diamonds 96 % Medium
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Cyberslot Megaclusters 96.36 % High
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Viking Quest 96 % Medium
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