It's still an efective, modern and inteligent movie. The way Corman uses the low-budget sequences to create a movie that has more to say than the title and synopsis could show. And Ray Milland has a perfect performance in a surprising narrative that isn't just like many sci-fi classics of the 50s and 60s, which ruin a great idea with some bad directorial decisions, unconvincing "happy endings", etc.
Having watched all the Corman/Poe films, I didn't expect a lot from this, but I was pleasantly surprised. The film veers more towards serious sci-fi than campiness, and mostly it's successful. Milland's performance is classy as always, and the ending's creepiness is top notch.
Thinking about The Lost Weekend (1945) made me want to see more of Ray Milland. At the beginning I liked where it was going, it had sort of a slight Hitchcock feel and I'm not talking only about the playfulness in the house party scene. But overall it was a very unenjoyable film with a weak plot, for todays standards filled with cliches making it unbearable to watch.