(Context: Ludia is running a survey right now that asks this question…)
I initially tried to leave this empty, because none of the options really jumped out at me (More dragons? New dragons come out way to fast as it is! New game modes? Maybe, but I still loathe the addition of brawl. More space? Meh, there is already enough to hit the 100 dragon cap.)
…and after finishing the survey, I realized what I really want, and (bonus points!) ought to be pretty easy to implement… more quests!! I seem to have run out of story/quests, which is a bummer as they were the main thing driving “progress” in the game. It would be nice to have more, even if they aren’t tied to upgrades (besides leveling dragons).
Another thing that I wouldn’t mind having is actual decorations. I’m talking about “buildings” that are purely decorative (have no game function besides looking pretty) and can be purchased for wood/fish/iron. (This might also help folks that have trouble spending resources!) These could be things like trees, flower beds, decorative rocks, dragon perches…