This VN has the single most mindblowing plot twist ever put in a VN. The plot spends 4 routes perfectly fleshing out the characters and introducing both physical and metaphysical concepts that will be integral to the story's solution while keeping all the ends loose, and then on the final route wraps it up in such a spectacular way that will leave you K.O. for a long time before you even get out of the shock to continue reading. Get a flowchart though, you don't want to risk missing the true ending.