I will assume that you have never seen any of the Liar Game adaptation (J-Drama + movies, K-Drama) and the manga.
I recommend watching the Japanese versions first, since it starts out in a similar way with the manga.
Many things were changed though, like the characters (no badass Fukunaga like in the manga, instead we get a mushroom-head cross dresser Fukunaga ), the way the games play out (though the outcome is still the same), and others. The Japanese version also put emphasis on the games themselves, so expect to not see major character developments in its entire run.
At least it is enjoyable, though.
After that, I recommend you to watch the Korean version, too, since the premise was entirely different from the original Liar Game.
It also feels like a completely different experience, compared to the manga and the J-Drama.
After all that, you may want to check the manga for the games that were not adapted in both versions yet. They are really good.
Or you can read it from the beginning for the best experience.
