"Anniyan" was a critical and commercial success upon its release. The movie's unique blend of genres and its exceptional production quality made it a benchmark for Tamil cinema. The movie's success can be gauged by the fact that it has been remade in several languages, including Hindi and Telugu.

The movie's legacy continues to endure, with "Anniyan" being regarded as one of the best Tamil movies of all time. The movie's influence can be seen in several recent Tamil films, which have attempted to replicate its unique blend of drama and suspense.

The movie explores several themes, including identity, trauma, and the human psyche. The film's portrayal of dissociative identity disorder is both sensitive and thought-provoking. The movie also touches on the theme of social isolation and the consequences of not addressing mental health issues.

For those who have not seen "Anniyan" in HD, the experience is a treat. The movie's visuals are crisp and clear, with vibrant colors that bring the story to life. The soundtrack, too, has been remastered to provide an immersive audio experience.