So, I'm going to make a lot of assumptions with my post.

CoC has given themselves a pretty good reputation by having a game with a ton of in-game purchases, but without doing it in a way that ruins the game. There is literally nothing that you can do with buying gems that you can't do without buying gems, with a little patience.

They seem to be deliberately avoiding the majority of popular things that social-driven games due to cause addiction without trying to really hide it.

So, CoC keeps you coming back to the game because of your shield duration. But you don't HAVE to come back .. it's just helpful. They don't have daily challenges. You don't "gift" your friends .. donating troops is a little different and more tactical. It's not Farmville. You can't buy a "double your resources forever!" which would force everyone to buy it to stay competitive.

I don't think they'll implement this, because "daily" challenges is so ubiquitous that it's kind of transparent.

I'd love to have single-player bases to attack ... ESPECIALLY if I had to do it with a specific army composition, instead of just relying on overwhelming power. If they do it, they'll probably try to come up with something a little more unique than "daily" challenges.

My vision is one of two things ... 1) Some kind of weekly or seasonal "tournament", where everyone is challenged to attack the same base (or bases), using a pre-determined army comp and army levels. 2) With or without #1 above, a competition for who can destroy the base using the fewest/cheapest total units. Ties would be broken based either on how many units survived to the end, or how long it took. You'd probably have multiple winners, based on some grouping like trophy-range or something.

I think this would be fun. But it would also distract from wars. Maybe each clan would work on solving the problem together, and the best attack for each clan is registered. Maybe the reward would be gems, maybe clan xp.

But, it'll probably never happen. It would distract from the wars. And they would have to put constant effort into designing these bases each week. And if they decided it wasn't worth it, it would be a pain in the ass to remove the feature without alienating a ton of customers.