The most impressive part is that they're actually faithful recreations of the IRL TCG art of the era. Someone had to redraw these as pixel art and I salute them.
Something important to add about this, is not only is the art like, amazing recreations of the original trading card art
But the game is a black cart game. That means it's ACTUALLY an original Gameboy game that happens to have color on a gameboy color
So not only is all this card art in the game, it also has to have BLACK AND WHITE VERSIONS TOO. And they also look AMAZING. Not muddy and impossible to discern wtf you're looking at. Just absolutely fantastic.