Pro Yakyuu - Pennant Race is actually a different game to the US Great Baseball release. Pro Yakyuu - Pennant Race released later and is more advanced with an overhead view along with having different teams/leagues.
As for Korean games, the only one that might be considered official is HiCom's Gaegujangi Kkachi. HiCom did officially distribute some SMS and SMD games in Korea, but it's not really clear what their relationship was with Samsung. The other Korean games are mostly in English anyway.
Edit: Looking at the SMS games which ran in SMS graphics mode as opposed to MSX hacks/ports which ran in SG-1000 legacy mode;
94 Super World Cup Soccer No
Agigongnyong Dooly Yes - The Dinosaur Dooley
Dallyeora Pigu Wang No
Gaegujangi Kkachi No
Janggun-ui Adeul Yes - Street Hero
Jang Pung II Yes - Street Battle
Jang Pung 3 No
Samgukji III No
Suho Jeonsa Yes - Power Block
Super Boy 4 Yes - (Fully English)
Toto World 3 Yes - Cave Dude
Some were localised for the Australian "4 Pak All Action" release, whilst others were localised for US Game Gear release (runing in SMS mode). Super Boy 4 was already fully English.
94 Super World Cup Soccer and Jang Pung 3 seem to just have Korean on the title screen.
Dallyeora Pigu Wang has Korean on title, team selection, and game over.
Samgukji III has Korean on title, intro, and player selection.
Gaegujangi Kkachi has Korean on title, intro, inventory, shop, and start/end of level.