Pros: Same game as Tetris Attack. = Excellent, with many fun modes.
Cons: Pokemon theme overdone. I liked it better with Yoshi and the gang.
The bottom line: Play it with the volume down. Try not to remember how great it was with the Yoshi theme.
Ah, good 'ol Tetris attack. In Japan it had a different name. But in America, it was decided that the consumer would be more likely to purchase a puzzle title if it somehow included the name Tetris in it. Unfortunate, because while Tetris attack had some really great puzzle gameplay, it had nothing whatsoever to do with Tetris.
In any case, the title was a minor success, and remains one of my favorite Super NES and Gameboy titles ever. With very well differentiated Marathon, Stage Clear, VS and PUzzle modes, Tetris attack had superb replay value.

Years later Nintendo decides to repackage the game with the Poke' title and here we have the result.
The first thing about Pokemon Puzzle League on the N64 and Puzzle Challenge on the GBC you will note is the almost absolute mimicry of the original title. The animations of the pieces, the pictures on the pieces, the faces that appear when you top out, even some of the stage and round clear music, is unchanged from the SNES and GB originals. But the fun, stylized Yoshi characters are gone. The great, and I do mean great music is gone. Replaced with Poke-blah blah blah. Especially in the case of the N64 game, the game is actually made worse than its predecessor by the horrible soundwork which even a fan will find repetitive and annoying in no time at all. Which is sad, because all the game play modes that made the original a great and original puzzle game are here for you to enjoy.
I must say, though, that the GBC version of this title has one thing over the original classic GB Tetris Attack. Can you guess what it is? Why, it is color, silly! The Game Boy version of tetris attack was fun, but the black and white screen made it far more difficult than its SNES counterpart. So here is the only reason you would want to buy a new copy of Pokemon Puzzle Challenge over a used copy of Tetris Attack. It's in color.

And if you play it with the volume all the way down, you probably won't get too annoyed. And if you've never played the original, you won't miss the wonderful music.