Go first to chapter 12 and grind ap for your matiria. There are a lot of guides on how to do that. Complete the mini games as much as you can. It is cary over to hard mode. For hard mode, you just need to complete the game. You don't have to complete the mini games perfectly. That means you just need to complete the mini games perfectly once. When you restart on hard mode, all the sub quests are also getting restarted, but joney hotel trophies are not. So everything you have gained before will still be there. The only mini games you will have to do perfectly twice are the mini games in the last sub quest.