basics:
1. swap 3 game
2. ONLY 20 levels will be designed. randoms.
3. a custom design option where people will be able to put the photo they want (but needs approval first)
4. holes and blocks, ice and smash, number of moves, all will be designed GUI by users who purchase the app for 0.99$
5. all level designed by paid users will need verification and approval from administrator
6. if a user is able to get 10 level published, money back or a gift will be given to them.
7. it must be VERY simple so that every level of users are able to create their custom level difficulty and send it to the admin.
8. the game will be free WITHOUT any adverts for all users. free or paid.
9. free users will be able to play level designed in house and by users who are able to get their level published.
^^^ This is where you need to spend a while.
Your game is simple. I can make this game in a day.
But your list of custom functionalities is making this project a bit harder than paying $15 for the game asset.
Look at points no.: 2 , 3 , 4 , 5 , 6 , 7 , 9 - and you say it's easy job
"Buy $15 asset and done - just simple changes and done" - this is "NO-GO" like that.
Good luck.
Best regards.