An explanation of the three particular mini-game types I mentioned in the now playing thread.
Shoot-Em-Up: Simplistic, unless you're trying for Superb. Just shoot the targets - the usual call and response. To get the Superb, however, not only can you not miss any of the targets, but you can only clip them (that is, just slightly be off) a few times too, which is a bit strange considering the Perfect requirement (just shoot them all down).
Moai Doo Wop: Another call and response. This time, the difficulty comes in replicating the other moai. Sometimes the game can't tell a tap from a hold in this one. The second one involves a slow section at the end. Barely any cues, and to make it worse, you have to perfect that section to net the Superb - it's one of the three objective lines.
Remix 6: This remix uses Space Soccer leading into Lockstep. Why is this bad? Well, Space Soccer has a massive window of error in the pressing, while the transition to Lockstep requires precise timing to lock down, since you have to fire right when the Touch Screen goes green, no sooner (and you won't get Superb if you miss all the transitions). While it isn't quite as bad as it could be most of the time, since there's someone in the back keeping perfect beat for you during SS, there are two times where they toss the ball, and right before it gets to the hit zone, it swaps to Lockstep.
Just to show how bad this is, in Remix 10, they perform a transition from Shoot-Em-Up to Lockstep. I've never missed it. I've almost always missed the one in Remix 6.