from what I can tell each card has an HP number and 3 rectangles that look like elements (with some of them just having a block of text there). They all have a uniform back, which shows that they were intended to be played like trading cards.
The most i can figure is that it worked like an oversimplified version of the Chrono Cross battle system. I.E. one attack would let you use the first element, 2 the second, three the third, etc, and Characters like Dario and the Summons seem to just have a single block of text as an ability.
There also appear to be 3 versions of Serge and 2 versions of kid. Lynx, Serge, and Kid all appear to have versions with holo-foil backgrounds. The rest of the characters seem to have backgrounds taken straight from the game. They seem similar to the Prism cards that were released for Chrono Trigger. The cards that have white backgrounds and lots of text appear to be cards with the rules to the game on them, but I can't read japenese so I have no idea what they say.
If someone here does buy these we should see if we can scan them, figure out the rules, and then load the image files into apprentice (a free program for playing TCG's online) or something similar and see if the game was any fun to play.
