Pokémon Trading Card Game is the video game incarnation of the popular Pokémon Trading Card Game (Pokémon TCG). It features digital versions of the first three sets of real-life trading cards, along with exclusive cards that are not available outside of the game. Normal gameplay involves finding and battling other trainers and Masters, eventually becoming the Champion and earning the Legendary Cards.
However, gifvex instead decided to glitch out the first battle and confuse the game into reading deck contents as code. This allows gifvex to reach the game's credits in just under 3 minutes. For more information, see the authors' comments.
We also have a similarly short run of the sequel, Pokémon TCG2.
You can watch the complete run being played back on a console.