Its a Spike Chunsoft game. The story gives you a lot of questions that leaves you questioning a lot of the subplots until it begins to twist back into itself to get all the answers.
The puzzle rooms are mostly self explanatory, but the repetition on some can be a bit annoying. The rest of the gameplay is generally just a VN with a bit of simple Point-N-Click to find some clue.
Overall, if you like Spike Chunsoft games, then you'll like this one.