keeveek: look for EMPIK ;-)

Remit: Thank you for all the replies so far. I went through Empik's, Media Markt's and Ultima.pl web pages, but none said the game was available. My best bet seems to be the Game Over store in Krakow. It's also conveniently located next to the Old Town. I'll probably also look in the chain stores (such as Empik and Media Markt) as well, in case they have a left overs bin or similar if I come across them. The same goes for large department stores I might visit. I'll see what happens and give rep later, in case someone comes up with a good store still.

If NDS never was that big in Poland, I guess the game will be in english. I remember getting The Legend of Zelda: A Link to the Past from Germany as a kid, when I knew basic english. When we got home from that trip I noticed the game was in german and couldn't understand a thing. Somehow I managed to finish it though, but got stuck a few times :)

keeveek: I have an idea :D Judas orders the game on allegro and receives in GOG.com office, and OP visit's GOG and gets the game
After that they go to drink some beers
???
PROFIT! ;p