The Homeworld series is great with fantastic campaigns (minus Homeworld 3 I’ve heard, not even played that).
I’ll also throw in a classic Imperium Galactica 2 because I still think for a 90s 4X RTS it has so many elements that I’ve just not seen replicated since. Though usually short and quick, it has fully simulated and controllable space and ground battles; espionage; diplomacy; you assign your unlocked tech to hard points on your ships… It’s Stellaris but better in most ways, imo.
Unlikely to be it since it’s nowhere near from the last 10 years, but CITY 2000 seems like it could be similar at least artistically?
I think the best I can recommend is looking through Steam, searching for “London” and the mystery genre. I didn’t quite catch anything there that fit at a glance, but maybe you will. Similarly could be done on GOG, since it sounds like it could potentially be an older game? Or itch, but maybe the best way to search for that would be by googling london missing friend mystery site:itch.io.
I’m assuming a modern setting, with no supernatural elements and the mystery genre, so that’s the best I could do. It’s going to be very hard to find something without some details being fixed. Point and click? Photos or isometric? Is the player character visible? Do they have any identifying details? Does the pub have a name? Anything like that could do a lot.
You say you watched someone play it on youtube then you might be able to search your youtube viewing history?
This seems like it fits more of a management/strategy type vibe to me.
Maybe you hear news of the 10 greatest knights of the realm coming to save you. But you don’t know what they’re great at and you only have a limited amount of instructions to give them.
You could have the first knight leave hints by telling him to leave marks in specific places. But he might be the best at combat and would be best sent against some of the other monsters guarding the path. You just don’t have the information.
But honestly, I’m not sure if that makes a player feel trapped. They have power to change things. Maybe you steadily take away that power? I’m just not sure how.
Very interesting question though.