Not perfect scores/grade, but rather how to pass them without much frustration. =P Also to note I left off right after completing R31.
There's a way to hold the 3DS to make the controls easy to manage. Simply hold the 3DS upright as opposed to laying flat like you are tilting for a marble game. It will look like you are holding a steering wheel.
R5: The one where Fondue eats a lot.
Holding it the way I told you, I noticed steering left and right I can tell at what angle I need to register a side. The trick to this minigame is that I can hold my position waiting for the food to reach fondue...
R13: Samba de Amigo minigame.
I love this one. Don't bother tilting I noticed that simply moving the 3DS like to mimic the actions shown on screen it will register! To do the raising, just move the 3DS above your head. I don't know if this is practical for the harder versions of the minigame but it worked for this first one.
R16: The punchout style fight.
Hold it like I told you, tilting left and right I don't have much trouble. You do have to be precisely in time with his punching, so it can be tricky. Watch the guide for his forward slam. Instead of tilting I noticed lowering the 3DS in timing registers. This is how I managed to dodge this attack.
First off, screw this minigame. This is probably the worse one in this game. Thankfully not all the minigames are this frustrating.
My first attempt I thought you had to line up the target cursor with the enemies but they pass by too fast. The way the minigame is set-up, it confuses you into playing like a rail shooter.
Once again, hold like I told you. I the neutral position seems to target the upper enemies okay. The lower enemies I just need a small tilt away from me. Left and right behaves. The trick to the minigame is that as long as you are on the side you aim at, You will just auto-target anyway. It was just a matter of timing my A presses.
I haven't gotten to minigames after R31, I completed it like an accomplishment and quit for the day.
This thread I think will be updated as I play the game.