The five most popular questions about the content of Million Dollar Secret Season 1, excluding the overall plot and ending, are:

1. How do the challenges and games work, and what strategies do players use to win clues or avoid elimination?
2. What role does the host Peter Serafinowicz play in the game, and how does his presence affect the show's tone?
3. How do the contestants interact with each other, and what kinds of alliances, feuds, or emotional moments occur during the competition?
4. What twists or special rules are introduced during the season, such as the ability of the Millionaire to transfer their prize to another contestant?
5. How does the identity of the Millionaire influence the gameplay, and how do players try to keep or discover this secret?

These questions reflect viewers' interest in the mechanics of the challenges, the social dynamics among contestants, the host's involvement, the strategic twists, and the central mystery of the Millionaire's identity.