Okay, so maybe I was a bit abrasive in that post in terms of my personal opinions and I don't want to give anyone the wrong idea here that I think Thousand Year Door is not a good game. I'll try to explain my rather unpopular opinion on why I don't like Thousand-Year Door as much as the consensus around these parts, and why I personally think Thousand-Year Door isn't that hard to top.
I firmly think that the original Paper Mario outdid Thousand-Year Door already, and that game did nearly everything Thousand Year stumbled upon, barring a few things I will commend Thousand-Year Door for improving upon. The Thousand-Year Door introduced too many bad mechanics for me to enjoy more than I enjoyed the original Paper Mario 64. I will get out of the way to say that I prefer partners having their own HP than what 64 did but that's pretty much the only upgrade I know about or at least was significant enough for me to remember. It would be great if you point out other improvements that Thousand-Year Door did, but I believe those improvements are not enough to make me like Thousand-Year Door over the original Paper Mario.
First of all the game has a lot of padding, more than Paper Mario 64. I don't like having to go back and forth in the sewers, go to that area where you need to reveal the map and Professor Frankly's house to reveal exactly where to go next. I don't like traversing the same areas again and again and use the sewers as a hub thing like how Partners in Time use time holes to instantly warp to another location to forgo cohesion; one of the reasons I find Forever Forest memorable is the gradual atmosphere changes between Toad Town and Forever Forest, unlike Creepy Steeple where you use a Warp Pipe to instantly travel there. The worlds in Paper Mario 64 are connected cohesively rather than resorting to a Warp Pipe to transport you there. Another thing I really dislike about Thousand-Year Door is the shine upgrade system. In the original Paper Mario, all you had to do is hit a block and you can upgrade your partner immediately. In this game, it works similarly, but with unnecessary layers of complexity added to it: now, you have to find several Shine Sprites instead of one and if you want to upgrade your partner to upgrade his stats, you have to trudge back to Merlon's house every. Single. Time to upgrade him. Because of this, I sometimes forget that I have enough Shine Sprites, and I realize that in the middle of the dungeon, only for me to forget later on. Thousand-Year Door was also very content with time wasters such as "I love you" and the General White mission, none of which I recall was in the original 64 version.
The Creepy Steeple is very notorious for the back-tracking required but Flower Fields is a similar equivalent, so I'm not going to bring it up. However, Thousand-Year Door has very linear hallway-like landscapes: from the forest from the Creepy Steeple to the train in Excess Express, to The Great Boggly Tree and so on, with a few exceptions for more open-like areas like the snowy area and the main Glitz Pit hub. Glitz Pit was memorable for pretty much the wrong reasons thanks to these weird restrictions and Excess Express was something I personally found to be on the boring side. The Puni mechanic was annoying in The Great Tree.
I really dislike the audience gimmick and I think it taints an otherwise very simple yet elegant RPG. I don't like having to scan the audience to see who will throw a rock or Mushrooms at me, nor do I like bucket drops and stage crap falling on me and having to be wary of that as well. The slot machines, they're luck-based and they have the potential to totally flip the battle against you if you have bad luck and land on a Poison Mushroom. Finally, some action commands feel really arbitrary to use, and some changes I feel don't need to be there. Tattle and using Star Powers worked fine in the original Paper Mario, now you need to either waste time to pointlessly line up the circle with the whatever just to get a battle log for enemies or draw a lot of circles around the enemy to deal damage and other crap like that that I don't like.
The music in Thousand-Year Door I personally didn't find memorable at all aside from The Great Boggly Tree and that chapter itself was annoying to play through already. The sound design was in my opinion a large step down from Paper Mario 64. Jumping on enemies with the right action command isn't as satisfying as it was in 64, with the sound effect simply not as impactful, and I absolutely hate what they did to the Zap Tap badge sound effect when an enemy gets, one of my absolute favorite sounds from 64 was seeing enemies get shocked by you. Boss fight music such as Tubba Blubba, Crystal King, Koopa Bros., and General Guy still ring very clearly in my head, despite not having played 64 in such a long time while I think the battle tune in Thousand-Year Door is a bit on the insipid side compared to the boppy and dance-y tune that 64 had.
Partners were a great improvement over 64, something Thousand-Year Door blessed upon, but they still remain relatievly static throughout the game aside from one-liners here and there in reaction to some scenarios and they're rather uninteractive. In other RPG games, all party members are active and alive, and will interact with other party members and build relationships with each other. Here, they feel like talking tools, and while the problem isn't as bad as it was in Super Paper Mario and better than not speaking again as they were in Paper Mario 64, it's still in need of improvement in accordance to other RPGs with multiple party members, the Mario & Luigi series included. A reason Huey and Tippi are very beloved because they're far more active and changing as the story goes on than the other partners. Vivian is one of the most popular partners in Thousand-Year Door for the reasons I had stated as she changes when the story goes on and she eventually joins you; she's far better than Lakilester can hope to be. This is saying much, because partners are one of the major selling points of Paper Mario in my opinion, and seeing them given more interaction than what they got in Thousand-Year Door to the level of RPGs with multiple party members would be amazing.
I admit I haven't played too much RPGs, but nearly every RPG I played so far (which is not much), I had more fun with them than I had with Thousand-Year Door, and that even includes other Mario RPGs like Superstar Saga (not going to mention the other Mario & Luigi I played because I'm heavily biased for nongameplay reasons). I might be a sucker for nostalgia as well for greatly preferring the 64 version over Thousand-Year Door but I personally found not much stuff to be impressive in Thousand-Year Door when I personally feel it's outclassed already by the original Paper Mario so I can't help feel not too impressed by Thousand-Year Door when a lot of stuff done in that game the 64 game did with flying colors. If I want an action RPG, I'd play Tales games or dungeon crawlers. If I want a better narrative experience, I'd not play a Mario RPG. If I want an RPG with action commands, I'd play Mario & Luigi or the original Paper Mario. If I want an RPG with fun and memorable characters and character interactions, again, I'd rather go with Tales of Symphonia.
I understand that Paper Mario does have its own niche, but I think the niche is very small, so it's hard for me to identify games that do on the same level on what Thousand-Year Door is trying to accomplish; being an accessible, starter RPG that anyone can play. But in terms of how it matches up in other RPGs, I feel the mechanics and narratives are outclassed.
