We could talk about hopes and dreams for the modding system, at least.
Since we haven't really seen how the game functions under the hood yet, I'm not sure what all features the engine will have. For example a mod like Harvest Moon (probably not gonna do one, but it's a good, simple example) would have some required functions just for the basic experience.
-A custom map for the game area
-Plowing, planting, watering, fertilization, etc.
-Individual timers for the various plants
-Some way to handle harvesting and a much larger inventory, money is probably in the game already
-Day/night switching, stamina
-An item crafting system
-NPCs for the shops and the dating sim part
Is there anything in that list that sounds impossible?