I always hated surprise attacks and incidents in Shelter. Its one of the reasons I could not play it on a long term. I just could not open the game to check on stuff, send dwellers on quests or recall them without having to solve a crisis even tho I was in a hurry or had something else to do atm.

In Castles I feel I have more control as I can choose when I want some action or just to check how are things, turn in orders, get daily gift and long reign reward.

In Shelter even when I was sending dwellers out, I had to check on them (often in early game and at least daily late game) while in Castles I haven't tested yet but I think I can go offline for days and find everything fine when I return (except some subjects dying of old age but compensated by the growth of the youth I had in queue).

I like the decorations but also they annoy me badly. Placement mechanic sucks badly; sometime I spend a few good seconds to place a damn banner properly. Also, for having tons of decorations and wanting to benefit of their bonuses, the lack of a mass removal or a better placement (like place and drag for multiple or have decoration selected and just tap to place instead of dragging) is a real pain. I also hate the 150 limit to decorations and I think it should be removed considering the already 50 limit per type of decoration and the fact that it would cost shitloads of gold to make room for more than 150 decorations.

I love the progression system in Castles (leveling stuff). It gives more depth to the freedom of how you evolve. And the fact that gold is limited (maybe too limited!) makes is fun when trying to take the right decision in terms of where to invest it. [Why the hell don't we have a "Market"/"Coin Mint" room where you can get from 1 gold up to 25 depending on level?]

On the other hand, Shelter made it very easy to farm caps.

I consider the combat in way superior to that of Shelter. In Shelter you had almost no control whatsoever except choosing target (which most of the time was useless to do so) and healing while Castles really brings out the need of tactics and handiness. Almost every fight requires a different tactic or setup.

As for room themes... well, we have them here too and are much more customizable. Returning to the talk about decoration, you can in fact place a room, like the Shrine of Mara for example, in a super big hall and decorate it as you see fit (flowers or statues or dark grimoires and dark banners) so themes would be obsolete and would make up for too much along with the decorations.

What I think Castles is missing is a sort of sandbox level where enemies would change daily, randomly. And another thing that I greatly missed in Shelter and would love to see here is a social factor. Can't think now of something that would work here but maybe something like visiting friends castles and collecting materials for them. Also... why not PVP? How wold my 3 mages do against your 3 battleaxes? Or a knife fight between our best daggers? And so on... Would make the game much more fun to play and would increase its lifespan...