This is a movie about a guy who
can't escape his dead ex-girlfriend. He hooks up
with a new love (Abigail Hardingham), but the dead
one (Fiona O'Shaughnessy as the titular Nina) just
can't let him go. Although the premise is macabre,
it's not really either a comedy or a horror movie.
To be honest, the entire movie is a straight drama,
which is in its entirety just an extended metaphor
for how difficult it is to clear out the baggage
from previous relationships.
It is a very tedious film to watch, although it's
filled with nudity and sex. Metaphors can work
within a movie, but they can't BE the movie.