Without a doubt the most challenging survival horror game I've ever played.
The gameplay is really original too. There are 10 different people you play as and each one has the ability to sightjack, or look through the eyes of other people. You use this ability on your enemies to get through each stage. Some of the characters you play as have weapons to defend yourself against the 'shibitos'. However some characters dont have weapons and you'll have to rely on stealth, sneaking around, and using distractions to get by your enemies.
Each stage has 2 mission objectives. However, on the first playthrough on a stage you only have to do the first mission objective. You can play through the stage again later to accomplish mission objective 2. In most stages, you have to do some exploring to find archive items(can pretty much tell you what is going on in the game) and you have to do some things that are required to unlock new stages and mission objectives.
The story progresses over a 3 day period in a village called Hanuda. There is a strange red liquid that surrounds the village. However I wont give spoilers to the story. If you're a fan of survival horrors or trial-and-error games, definitely give this game a shot. Its worth it.