Developed in partnership with OG's sidekick Golden Hero, this slot will take you on an underground j ourney to a mysterious alchemist's laboratory with all the. Return to player. Big Time Gaming video slot review of Millionaire Mystery Box that contains Free Spins ✓ Bonuses ✓ Wild and Scatter Symbols. This game is all about the gameplay. Instead, this 5-reel slot offers an amazing ways to win. Millionaire Mystery Box is an online slot created by Big Time Gaming that is built round a 5-reel, 3-row format. This mystery box game is a super fun PowerPoint that you can use in any lesson, whether you are teaching online or in the classroom. Try Who Wants to Be a Millionaire Mystery Box slot online for free in demo mode with no download or no registration required. Mystery Box is a reel, line online slot game with multiplier, hold and a dice games theme you can play at 20 online casinos. Game. Millionaire Mystery Box has a slick land-based feel and. %. Features include a. You need to match the magical symbols which are all scatters. Try Mystery Box slot online for free in demo mode with no download or no registration required. There are ways-to-win. It is straightforward and easy to understand. To play the game. . The Millionaire Mystery Box slot machine doesn't have traditional paylines. Return to player. Enjoy Ways to Win. Millionaire Mystery Box is a ways slot designed to deliver a game to suit every type of player.