what in the world will i teach?

so right now i'm at the point where i worry about what i want to teach the children that will be using my (hopefully beautifully created and functioning) application. My main two goals are to make it fun and educational, but what do i teach, and how can i make it fun for kids? SO, my thoughts are this:

1. storytelling- if i create a theme and have children complete the story and decide the coming events, they'll be interested to see how it turns out
2. choices are very important- either have kids create their own steps or let them choose from many options
3. interactive and engaging- keep them going! introduce blocks, problems, mysteries, and new learning tools so that they don't drop the game before they finish
4. i'd like to teach teamwork, so my thoughts on how best to do this is to create different sprites/characters and allow the user to become one of those characters, deciding their actions. if each character is given a role with strengths and weaknesses (for ex, a doctor who has medical knowledge, can work well under pressure, etc) then children can decide who to use for what specific task. 
5. if kids are given a theme and an overall goal (for ex, an animal is in danger or injured, who's expertise do we use to help save them in the allotted time?)- kids can learn teamwork by not always making their character do the work, and could potentially work with other friends, listening to ideas and deciding the best actions together.

i still have a lot of fleshing to do, but hopefully it'll come together soon.