The structure of the story (or lack thereof)
Overall, I thought the movie itself is okay, doesn't reach the brilliance of the first one and doesn't match the zaniness of 2 and 3, it's pretty much on the same level as the 4th one, although I do like the lore-building aspect of that one better.
However, one thing I thought was very clever about it, was the structure of the film. It kind of reminded me of Cloud Atlas.
It picks up right where the fourth one left off, albeit some time has passed. But then, it starts jumping between all sorts of different "realities" and "universes", while still telling the same story, just in alternate timelines and different variations of it. I thought that was very creative. Phantasm has always been a series where the filmmakers' ambition is aces higher than the budget they have and it's wonderful.
I completely get why that threw a lot of people off, it hurts the coherence of the story quite badly and it could have definitely used a couple more drafts and some trimming, but overall, I thought that aspect was genius.
"Ever danced with the devil in the pale moonlight?"