Hoo boy, a lot to unpack here.
Let me first say: overall, very solid in pretty much every area.
I didn't get a lot of the story references to last year's jam either due to my poor memory or it was related to games I hadn't played, so trying to digest each wall of text was... let's say I appreciated the quality of the writing more than the quantity or details. Sometimes it felt like "jargon soup" during the expository scenes, which is unfortunate as the depth of world-building is impressive on the one hand but it pulls the audience out of the experience/ruins immersion to have so many WTF-is-happening moments. I don't know if there's any way of mitigating these issues while telling the story you wanted to tell, so take all this with a handful of salt. Other players may also be more in tune with the meta arc than I.
Music choices were good, seems like most SFX were RTP which is fine.
I kinda wish you weren't encouraged to pick a single team and double down on it. The relationship mechanic and how it impacted stats/skills was satisfying but it also meant I ignored characters for the whole playthrough. And, while I enjoyed the entire game, it was definitely too lengthy to do a second run just to see what other sidequests were there. (choice over-commitment and being unnecessarily long are criticisms I have about my own entry, so there's that...) I would have liked to see dialog branches or something interactive during story scenes; while the menu navigation was well done, structurally there wasn't much "gameplay" outside of battles and menuing.
Speaking of battles, I think 1-2 waves of jobbers could have been trimmed per "area". I get their utility as a chance to experiment with character skills and maybe drain some resources, but there came a point where I just started AoE-ing them down to get it over with. The fights vs. enemy contestants were much more mechanically interesting though it felt like giving them all Stimulants was kind of an artificial way of padding the fights out. Surprisingly the area bosses felt much easier than the 3-v-3 battles, and I usually cleared these in just a few rounds even with the auto-revive or other shenanigans. It seemed like each one had a cool gimmick at least.
The difficulty spike after the 3 main areas was curious. I had done all of the side dialog and was purchasing items like a madman so it didn't seem too daunting, but Buffet Harold in particular felt at times like his damage mitigation was unfair. (I also suspect, I should have remembered to hover my mouse over him to see what effects were modifying damage, but I forgot about that plugin until the following battle.) There might have actually been too many mechanics to keep track of. Like, it's great to see this level of complexity with a close-to-default battle system, and some of the synergies were just fantastic (Minotaur Harold's design was brilliant in particular), but there were also some things that felt like they should have interacted with one another that didn't; perhaps having a more uniform design with fewer unique gimmicks might have helped there. Side note, it doesn't look like any restorative items remove the DoT stacks from Dark spark type moves, even though the descriptors imply they should.
Final few fights were tricky, epic, and over-the-top. Ending was solid, and despite being out of the loop in many ways I found the wrap-up fulfilling. All in all, the character interactions were super well done once they really got underway.
Lastly, I wish I could award bonus points for this being such a love letter to Haroldness itself and a celebration of the community at large.