Most if not all words that are primarily classed as "nouns" can be used as "adjectives". There's nothing unusual about "prequel movie" (that's 373 written instances, but there are many, many more on the Internet at large.
A prequel universe also seems perfectly credible to me. It's slightly "quirky", since the word normally refers to a book, film, etc., narrating events which precede those of an already existing work, but such figurative usage is well within the constraints of both grammar and the need to be comprehensible.
I've no idea what OP might intend by prequel lives (what some reincarnationists believe in is past lives), so from my point of view it fails the "comprehensibility" test. That's not to say I couldn't be convinced otherwise. And a prequel game is obviously capable of being produced, so that collocation is fine.
Note that the only "awkward" aspect of OP's second example usage is repetition of the word movie. In contexts where both the original and the prequel are the same format, it only needs to be specified once (or not at all, if other contextual information makes it clear anyway). But that's just a style issue.