Millionaire Mystery Box (Big Time Gaming): Overview

Launched in November 2018, Big Time Gaming’s first branded slot Who Wants to Be a Millionaire quickly became a hot topic in the casino scene. Sadly, not in the best way. From the moment it was revealed, players speculated about what would happen if someone climbed all the way to the highest tier of the free spins feature. Soon after release, a community member shared a video showing the first known run to the maximum 50 free spins. The outcome was underwhelming: he ended up with only a 300x win which, for a game promoted with potential well beyond 20,000x, felt comically low. Since then, though, the huge wins piling up on Youtube and across forums have made it clear that Who Wants to Be a Millionaire really does have serious upside.

Millionaire Mystery Box is a slot built around the 2018 Big Time Gaming release Who Wants to Be a Millionaire. With play starting at just 0.20 on all devices, it uses a format that’s fairly atypical for Big Time Gaming and one we’ve only previously come across in Books of Gods (if memory serves). Featuring 5 reels, 3 rows and 243 ways to win, it includes a Mystery Box Reveal mechanic that can turn into any symbol, even special ones like the wild and scatter. As in the original, the real excitement kicks in once you take a seat in the Hot Seat, where you can land up to 24 free spins plus a multiplier reaching as high as 50x.

It fires up to the familiar game show theme tune, and the studio looks just like we remember from Who Wants to Be a Millionaire, neon-lit with the hot seat sitting behind the transparent reels. The symbol set is also unchanged, with 9 through A royals alongside higher-paying green, blue, red, and purple gems. The purple gem leads the pack, paying 25 times your stake for five of a kind. The 2x multicolored icon acts as the wild—limited to the three middle reels—doubling any win it helps form, and it can even multiply with other wilds when they connect.

Millionaire Mystery Box (Big Time Gaming): Features

True to its name, this take on Who Wants to Be a Millionaire includes a Mystery Box feature. It can appear only on the three central reels, and when a Mystery Box symbol lands in view, every one of them will change into a random symbol—wilds and scatters included. This can both help complete wins and improve your chances of triggering the free spins.

No Millionaire game show slot feels complete without a Gamble option, so Big Time Gaming has included one here too. In the Millionaire Mystery Box slot, it becomes available whenever you hit a winning combination in the base game, at which point you’re offered the chance to double it. In practice, you can keep risking your payout, doubling it one step at a time until you either reach the limit or choose to cash out.

In the original game, you were able to gamble your way up to 50 free spins. In Who Wants to Be a Millionaire Mystery Box, the approach is slightly changed. First, you must land 3 or more scatter symbols to enter the Free Spin round, which begins with 7 spins. To the left of the reels, you’ll see a ladder showing extra spins and multipliers. Each scatter that appears during free spins moves you up the ladder, boosting the win multiplier while also adding more spins. Gathering all 11 scatters required to reach the top awards a 50x win multiplier.

Hitting the top doesn’t automatically mean the spins are about to end, because every scatter that lands after that still adds an extra spin. As for potential, wins can reach up to 12,000 times your stake here—huge, to put it mildly.

Millionaire Mystery Box (Big Time Gaming): Verdict

In a sense, Millionaire Mystery Box feels like a blend of WWTBAM and Opal Fruits. It keeps the theme and foundation of the original, but adds enough new ideas that, at least in our view, it’s not just a different experience—it’s a better one too. The reasons are fairly straightforward. For one, it’s interesting to see Big Time Gaming lean into a more classic reel setup this time, especially considering they created the Megaways engine. And honestly, it’s also nice that the free spins gamble element is gone, since it was never something we particularly enjoyed.

It might not be Big Time Gaming’s most groundbreaking release, but it’s executed brilliantly, and the multiplier ladder suits the game show concept perfectly. Overall, it delivers a straightforward, no-fuss slot experience where you’re basically focused on pushing forward or pulling back. When all is said and done, Millionaire Mystery Box is yet another excellent high variance slot aimed at players who want the adrenaline.

If you want something with a more original twist, take a look at Monopoly Megaways, a branded slot based on the classic Monopoly board game and the second Big Time Gaming title to use the Reel Adventure mechanic. Or, consider Survivor Megaways – another branded release inspired by the well-known Survivor reality show.