It's a Spanish film where a serial killer targets the elderly in a specific community because after he kills them off, he sells their apartments to gay couples to make the area a gay neighborhood.

If anyone's watched this, is this worth watching or is it a shallow mess?

it is a comedy.
(dark comedy)
It is up to you.

I saw it at Oufest last year. It's actually quite funny and delightful. Kind of a screwball comedy. I would totally recommend it.