I will stay in Seoul and Busan (South Korea) for a few days in September. I would like to spend some time for shopping. I'm mainly interested in retro games (up to PS2). Are there any good shops, flea markets, night markets, etc. in the area of Seoul and Busan? Furthermore can you recommend any good Arcades (new and old games)? I'd be happy about some recommondations
You'll be hardpressed since The Korean game market was gimped due to their "We hate Japan Polacy" Try looking for Comboy systems that's what Nintendo hardware was called over there for awhile.
I don't expect to find a lot of Comboy stuff. I hope there's a decent selection of Sega Saturn aka Samsung Saturn and PS1 games.
Unfortunately as a passing tourist your chances of finding Samsung or Hyundai stuff are next to nothing. I just don't want you to be disappointed. Korea has a lot more to offer than just that !!