As a longtime fan of the Tomb Raider video game franchise, I'm definitely excited about what this challenge could entail! I think you did a good job of clearly including a hook, and a promise of what's to come once you have a few more details in place.

A few suggestions for this item, as you work toward getting it open:

I noticed that the folder item itself has an image and "coming soon" in parentheses in the title. You might want to think about doing the same thing here, to create a more visually appealing group item for potential entrants to look at.

I also think it would be advisable to get that survey you mention at the bottom of this item active; it's hard to sustain interest in an activity without a call to action and something for people to do right away. Rather than telling people to come back later or email you in the meantime, it might be effective to have a simple form with an email interest sign up, so you can start getting people on the list and communicating with them as you build the activity. If there are real Tomb Raider fans signing up, it could be helpful to engage them in pre-start activities like helping decide which merit badges to commission, or sharing their favorite moments from the franchise so you have some ideas to focus on.

Overall, this looks like a really fun activity that I'm excited for whenever it opens!