This is one I've missed somehow so I really can't advise you on the difficulty level.
I loved Ariadne, one of my all time favourites and would put Babylonia and Fishdom and Fishdom Spooky Splash at about the same difficulty levels. I have Rise of Atlantis too and have never finished it, had a glitch and reinstalled but still think it's probably not doable for me, so maybe we're about at the same level of expertise.
7 Wonders II was another one I really liked and was able to finish, I found Cradle of Rome difficult but I did make it through and liked it a lot, anyway if you haven't tried all of the ones I mentioned already one of them might fit the bill.