While there's a very well known Playstation puzzle game that's a Cardcaptor Sakura tie-in (Tetris with Cardcaptor Sakura Eternal Heart), but this one, which is an entirely orignal game, rather than a themed re-skin of an existing one, is not so celebrated. Having now played it, I can see a few reasons for that. Not that it's necessarily a bad game, but it definitely doesn't have the broad appeal that "Tetris with characters you love" does.
The biggest problem the game has is something I'll get to later, but the second biggest is that upon first playing it, it's not really clear what you're supposed to do. You choose to play as either Xiaolang or Sakura, and each stage sees your chosen character walking along a long transparent grid-marked road in the sky. Ahead of you, you'll see spinning Clow Cards in four colours: red, green, blue, and yellow. You shoot magic at them, and they disappear. Sometimes, you'll shoot one card, and a whole bunch of them will disappear, awarding you points.
What's happening here is that there's a kind of rock-paper-scissors circle involving the four colours, whereby shooting one colour will cause adjacent cards of the next colour in the cycle to disappear too, and they trigger the next colour, and so on. The cycle goes Red-Green-Yellow-Blue. In easy mode, it doesn't matter which button you press to shoot at a card, while in normal mode, each of the four face buttons is assigned a colour. If you shoot the wrong colour at a card in normal mode, it spawns a card of that colour. So, if you're smart (and dextrous), you can strategically place new card among the pre-existing formations to link together massive chain reactions and get many more points.
There's also a bit of a meta element to the game: each stage also has a meter for each of the four colours. The meters fill up as you vanish cards of their respective colour, and when filled to the top, you capture one of the Clow cards. Capture all four cards in a stage and afterwards you'll also get a fifth one. Get all the cards across the ten stages in story mode and you go on to play the extra eleventh stage and see the real ending (unfortunately, all the story scenes are the same with both characters).
Now, onto that biggest problem previously mentioned. What it is is that there's no playable modes other than the story mode (in which the stage layouts are identical every time), in easy or normal difficulty. I think it's a game that would have really benefitted from an endless score attack mode, or maybe even some kind of competitive mode. But you'll play through what there is in a few hours at most, and there's not much else in there, which is a shame. If you can read Japanese, there is some extra value in the very extensive Clow Card Uranai mode, which allows you to have your fortune read by various characters from the show, on a variety of subjects, using the Clow cards for cartomancy rather than the tarot.
Clow Card Magic is an incredibly cute game, and it's definitely worth the time of any Cardcaptor Sakura fan, since it does such a great job of capturing (ho ho) the look and feel of the show and its world. For anyone else, though, it probably won't hold your interest, and the re-themed Tetris is probably a better bet for you. (Apparently, the mode that appears in later Tetris games that builds on the ideas of that game is considered one of the great monumental challenges for Tetris players!)