Four short horror films, no linking narrative, although there is some decent Svankmajeresque stop-motion animation serving as transition:
A boy loses his appetite after getting a glimpse of something mysterious; a woman discovers her husband's corpse on the day of her daughter's birthday; four attractive young people discover an Ancient Evil (TM) in the wilderness; and a mother deals with the discovery that her nearly adult son is disturbingly violent and yet everybody worships the ground he walks on.
Production values tend to adequate-high, and effects are acceptable, but there are small issues with each section that leave the overall film feeling amateurish. They're generally small issues, and I expect the filmmakers to work them out for their next projects.
Narratives are disappointing, generally from the lack of resolution-- although inconsistent characterization and unimaginable motives plague the second, making it the weakest. I can enjoy unresolved horror shorts in general, but it doesn't work here, not with the way these films are implemented; there's too much dragging along at each end, suggesting a reveal that never materializes.
The first was my favorite, and I found it generally creepy, although, again, the resolution was handled poorly; there were also some instances of poor acting, and too much voice-over exposition.
The "theme" of XX is apparently that all four films were directed by women, but there's not really any significance to that. If the title wasn't so eager to let me know, I wouldn't have realized it, and it kind of feels like painting a handgun pink for marketing purposes, a little dubious. Still, it's not a big deal to me, just a title. But after knowing, a few things stand out: the inversion of stereotypes for the parents in the first film; the unwillingness to commit to any crazy-lady characterization in the second, even though that's the only thing that would give the story even a lick of sense; the self-important and overly long soliloquy in the final film. (The only thing that maybe stands out in the third is that none of the attractive young people decide to disrobe, as they do so often in similar films.)
I'd say that the first film is probably worth watching, but I wouldn't bother watching past that. Not worth paying money for. Still, there's no reason not to expect good things from the filmmakers in the future, as they find some better scripts and improve their techniques.