I think there are some pretty good moments in this film. I like several lines of dialogue that are fun and witty. Some interesting selection of music.
Character doesn't a knack of mixing the meta with melodrama; he goes dead in the moments when we're meant to simply feel its protagonist's pain rather than dissect it. It's an intellectual experience rather than an emotional one, but the ideas in play are so heady they're enough to sweep you away on their own.
For a film like this to work, the quotidian drama has to be as engrossing, if not more so, than its fantastical analogue, but you seem far more engaged by metaphoric possibilities than mundane realities. The film goes dead when it's just people talking in a room, which is far too much of the time. the girl indicates to the heavens, twitching and gesturing without ever getting under her character's skin, and the guy is flat and bland, not the sweet guy who makes you wonder why you ever left home but the genial dullard who reminds you why you left. (Eventually, the script calls on him to do more, but he hasn't laid the groundwork that would allow the sudden turn to come off convincingly.) The movie plays as if the production spent more time designing its monsters – which, to be fair, are quite impressive, especially on an obviously modest budget – than on rounding out its flesh and blood characters.