You’re asking for one of my absolute favorite genres…
If you’re only looking for real life liar games/variety, definitely try all of the seasons of Crime Scene (it’s coming back for S4 soon!) that has my favorite Genius winner, Kong Jinho as part of the cast. +1 on the Bloody Game recommendation, if you can stand Kim Kyunghoon from TG s3+4, try the Black Sheep Game too, but for me the contestants are a lot less capable/intelligent than that of Bloody Game and especially TG (TG is unrivaled in this regard). Maybe try Girls High School Mystery Class and The Great Escape as well, although, again, I wouldn’t say the cast members are quite as smart as the ones on TG.
If you’re also looking for dramas, I definitely recommend all the variations of Liar Game (Japan) that inspired The Genius.