Oh my god! I just got Re:coded and I had the same experience with Darkside. At first, I just thought that being a Japanese game (the island country inhabited entirely by computer pwning game masters) originally made for a cell phone, that this was the default difficulty of the battle. It wasn't until roughly 11 minutes in (or 12) that I beat the thing and then I realized I'd set the diff at Critical. I left it there since because no battle could possibly be as difficult as that battle against the buggy Darkside when I start to get new abilities. I'm just beginning in Wonderland now.
And A-Z, you can play CoM on your DS.

By the way... has no one seen those Final Mix videos?