Alex Thompson’s review published on Letterboxd:
The Ninth Configuration is a weird film. It's funny, mostly, until it isn't (and even then there's some really silly stuff that's silly on purpose though now used to throw you off balance) and kinda cheaply made with obvious sets that feel not even close to real. But of course, that's kind of perfect for a movie which wants to keep you guessing as to what's happening and why. There are long scenes of dialogue and manic action that might be off-putting if they weren't so well written and fun to watch (everybody here does great work, by the way, acting-wise). It's written and directed by William Peter Blatty and the guy knows how to do religious and philosophical questioning wrapped up in Shakespeare and Casablanca and Superman. It's a culturally literate script which only serves to heighten the craziness of the people on screen as they talk real smart about insane ideas. I'm rambling here because it's a rambling kind of movie. A messterpiece, given the crummy voice work in the early goings and the sheer lunacy of the penultimate scenes. Messterpieces are always interesting, though, this one doubly so thanks to the talking that plays a dual role of being totally entertaining and really interesting, philosophically.