"A single lie can save someone... A single lie can gain you many new friends, A single lie can change your whole life"
So.. the anime teaches us that Lying = good? Not really, however, if that lie doesn't affect others and it helps you achieve your goals and basically your life depends on it, well...
I'm gonna say this from the beginning, this anime is not something special, not something revolutionary nor unique, it's a pretty average series with a fine art style. But does this mean it's bad? Not necessarily, it does have some interesting characters and some bland ones but i would say it's bearable.
The story did not really progressed that much in these 12 episodes, somehow I'm fine with it, rushing series, even if 12 episodes it's bad(Although in some aspects the anime rushed way too fast, like the development of romantic feelings for certain characters). So our Hiroto is searching for a childhood friend, the whole point of him being on that Island is to search for that certain friend, but sadly in a whole season this topic is not touched almost at all nor he does any progress into actually searching, this pretty much gives me Classroom of the Elite vibes, playing mind games, manipulating, lying. Liar-Liar tries to combine all of these but sadly doesn't really succeed, many times the logic used for certain games doesn't make any sense, just made up things, like totally fantasy.
I would recommend this anime to people that are bored on a Saturday night and you don't really want to watch nothing psychological that requires you to squeeze your brain out , just you know, relax and enjoy, if you expect some awesome story and character development, etc, etc, i suggest you to not watch then, as i said above, Liar-Liar is pretty average, doesn't really stands out with nothing special besides the "waifus" that are not that many anyway.
So overall i give this anime a 7/10 that's more of a stretched out subjective score, because if i had to rate it objectively, i would say at best a 6/10 but if we ever get a season 2, it does have some potential.