I'd like this also, but taken one step farther by adding in some edutainment aspects and then scaling it with the intent that once children have emotionally bought into the game, it incentivizes them to learn real-world facts and knowledge in order to make further progress (if they're still holding onto their Pokemon and their Minecraft world after 5-6 years, I'd hope some future edutainment game could match that). e.g.

+ fill in a personal database device (see: Pokedex, mobiglass) to collect knowledge of and record 'sightings' of real plants, real animals, elements, chemicals, reactions, etc.

+ NPCs/locations with trivia challenges/minigames (main character name in Moby Dick, years during which the first world war occurred, etc.), plus a library to look stuff up in

+ type in what you want to do (ala certain early adventure games) like "heal forearm cut", "fish for walleye", "search for raspberries" = typing practice, spelling {although since almost no games seem to do this anymore, maybe it's just obnoxious and poor design}