March of the mini's is indeed an awesome game, love the lil movies in it as well about the fun new mario toy recall being really impressed with those when I got it on the GBA, reminded me of Warioware Inc. As for playing the first release of Theatrhythm if you have Curtain call... there's no real point I think, I beat everything 100% in The original release of that and looked over what curtain call offered was pretty much everything in the game I played and a tiny bit more so I didn't get the 2nd version of it, but if you started with curtain call, think you can just say you've also played what's good in theatrhythm.
Honestly, pretty much the only thing that is the same from the first release to CC is the songs and the character art. It's crazy how primitive the first is. CC isn't touch only, though you can play it that way, and that was the biggest adjustment for me. I was used to using the control stick and ABXY buttons to hit the notes. Dozens more songs on cart, including spin offs - and many more on DLC, including from series like Bravely Default, SaGa and Mana series, up to FF XIV, many more characters. And instead of this strange three round per game thing, you can play every on-cart song out of the box. And, a better form of adventure mode. I actually enjoy noting the differences between the two games.