Anime: Persona 5 the Animation: The Day Breakers 5z1w5g

This special provides some background to certain events (and a related short side-quest) that only receive cursory mention in the game. For those playing, the events take place shortly before the third palace. It's definitely not essential viewing, but neither does it do much to spoil the game - for those who have yet to play it, it provides a brief preview of what to look forward to, and for those who have played it, you get a short "Aha!" moment when you realize how it fits in. Anyone who fits in either category will likely find some enjoyment to be had.

For those with no interest in ever playing the game itself, I would steer clear, since its main draw comes from how it relates to the game, so you're likely to get vet little out of it.

I strongly suggest watching it after you play the game. It will work like a nice addition to the game. If you watch it before playing, you'll spoiler yourself around 20% of the game ('cause characters are introduced slowly, and this anime shows 5 of them in 20 minutes).
If you view it as addition to the game, its good (with some flaws, but that's OK) - nostalgic soundtracks, voices, characters, all that.
Dont try to watch it as a standalone thing.