Clear and clean problem statement; I appreciate it!
We tried so many already like Minecraft, which we purchased for our laptops but his internet couldn't handle being on my server.
The latency or Internet issues in general seems solvable? Did you explore it further?
We liked the concept of Adorable Home. Too bad that app isn't an online multiplayer, even for just 2 people.
That seems like a clear need-gap, The game seems to be built specifically to be payed by two people, Perhaps by transferring the phone to each other. Making it multiplayer would directly address the needs of long-distance relationship couples.
Are you planning to address this need-gap yourself?