Definitely a very well-put together show, and as was foretold, it's the last two or three episodes that really make it in terms of contextualizing the whole thing, but also really being self-aware of itself as a groundhog day loop, or more accurately, many-worlds.

Theme: Pretty evident from the beginning, so it's more a matter of the protag realizing it. In the sense of, as the Master says outright later, there is no rose-coloured life, only a variety of many different colours that, when mixed together, give you the variety of life. Colouration comes up again when MC-kun is trapeizing through the 4.5 tatami rooms in ep 10 (lel, ep 10 confirmed for revelation episodes), and each one is a slightly different colour/a slightly different part of himself. Forming a 3D/full colour image, as he says.
The Master is called such because he has no goals or expectations of life, and simply lives in the moment. Pretty much Taoism/10. Actually the whole philosophy of the show is pretty Taoism. Be flexible and you'll bend instead of breaking.
So yeah, end message is pretty simple and straightforward. "Treasure your ordinary life." But the way that it's told is what makes it compelling.

Symbolism
- Moths. Akashi-san's fear, what's infesting the tatami rooms, and what are finally unleashed when MC-kun finally grabs the thingie. Basically represent stagnation, literal mothballs, etc. The storm of white moths really conveys that nicely, though the screenglance of naked MC-kun sailing through the air to a dove was pretty pls. I did like his clothes and beard and stuff peeling off, since not unlike a chrysalis transformation himself, he's being born anew.
- Threads of fate. A thing.
- Keito and Kaori are pretty much constructions or pedestalizations of MC-kun's own psyche rather than real women, ofc. Overthinking is bad, living in the moment is good. I called Keito being Akashi in the episode that deals with that, though I wish I caught it sooner.
- I did really like how the last episode peels back the curtain and shows Ozu as he actually is, instead of as he is through MC-kun's bias. As a true disciple of the Tao now, he's able to see the world as it is instead of through a binarized perspective.
- 4.5 tatami mats. Stuck in his psyche, stuck in his own box [room], etc. And so on, if there's any particular motifs people who've seen it want me to speculate on, just say so.
- Oh, I also want to mention the old fortune teller as someone associated with cats (in ep 12), who goes from the clock-manager (beautiful moment of revelation there) to a seemingly normal homeless person with a cat. Similar to the Master and Ozu, she loses her supernaturality when MC-kun loses his glasses on the world, but yeah.

Animation
Sometimes this was really effective, like in the episode describing the Master's desire to travel the world, sometimes there were some fantastic sequences (ep 10 and 11 come to mind), sometimes it was just more generally fun (100t balls gag, lel).
I think the mash-up of real life shots with animation cells drawn over them, while stylistically cool, didn't really add much to the story in terms of content (though boiling water as a trope for his pent-up [sexual] frustration made me rofl, and the childlike and petulant artstyle for his primitive libido was a nice touch). Sometimes the animation was nice but obvious (describing the experience of reading while literally rowing across pages), and sometimes it just seemed utterly disconnected (the seafood floating through the sky in earlier episodes). The latter at least certainly conveys a dreamlike quality, though, and it's definitely better than having no animation innovation at all.

Overall, a very well-put together anime with great writing and solid execution. However, it didn't aim high enough for my liking in terms of what it set out to accomplish, so it kind of leaves a taste of "well, that was well done" than anything else. I get the same feeling from some postmodern novels with great writing, but not a whole lot to say. However, I think if I ruminate more on the Taoism angle I could appreciate it more, since I think that'd give me an anchor to keep coming back to Tatami Galaxy and thinking about it. I'm giving it an 8 on MAL, but like most things that's subject to change.

WHY

WHY ARE YOU DOING THIS TO YOURSELF

YOU WERE DOING SO WELL BEFORE

BUT THIS

HOLY SHIT

I'M ANGRY