For a long time Sinnoh was my least favorite region. To make something clear, I still think it is a decent game. I actually don't hate any of the first six regions, any region prior to Alola can play and enjoy to varying extents. But since Sinnoh is I would say a fan favorite I think I can count this as a non-mainstream opinion because I think its just alright. It is like I am seated at a table with 6 gourmet dishes, and the 4th has more salt than I like eatting, but it is still edible. I do like the music and the champion.
One of the reason I don't rate Sinnoh as high is because it has my least favorite set of starters. I tend to pick my starter the first time based on simply the design that jumps out at me most. In the previous I found all of the starters in Hoenn really appealing to me, and was so torn, it was the toughest choice I made. When picking a pokemon in Sinnoh I found myself stalling, but for the opposite reason, nobody just really blew me away at a glance. I took Turtwig because I thought his final form was the best of the bunch design-wise, I kinda liked that he had a tree on his back. But there still isn't enough variation in style between the three for my tastes, I usually go for the design I think looks sleek and quick, in gen 1 it was Charizard for me, in gen 2 it was Typhlosion, in gen 3 Sceptile, but nothing represented that alternative when I got to Gen 4. All three looked very intimidating and brawny with a lot of stuff on them in their final form that looked like armor, I would have liked to have had more of a contrast. Take Kalos for instance, you have that in Chestnaught, a hefty warrior, while Greninja offers the oposite a svelte, nimble ninja, and Delphox has a colorful busy, fanciful design to represent the magician. All of the Sinnoh starters felt very "heavy" by comparison. Even a round, cute little penguin like piplup ends up turning into Bane from Batman by th end. So I needed more variety, even though they were all good pokemon to use.
While Gen 5 is typically associated with having polarzing pokemon, I think you could levy that same criticism against Gen 4. There are plenty of pokemon I like from Sinnoh Staraptor, Luxray, Togekiss, Roserade, Munchlax, Gallade, and the same is true for me of Unova, and likewise for every pokemon I like there is one that I don't like, Magmortar, Probopass, Tangrowth, Rhyperior, Bastidoon were all eyesores. I do think gen 4 has a very strong pantheon of legendaries, and the history of the region is interesting.
I love how in general in pokemon from gen 3 onward the role of the legendary pokemon became a central part of the plot completion in pokemon games, and gen 4 takes this to a new level. It introduces the legendary pokemon very early into the story, and their presence is always there in in the background, resulting in I think very good on world-building. I think it sure was ambitious to allude to pokemon essentially being God and the Devil.
As interesting as all of this is though, the region has a pacing that loses me frequently. The
the next gen games Black and White had a more lively storyline from start to finish. Even the title sequence is a story with N's coronation. You meet the leader of the evil team by the first town. They weren't playing around when they introduced Unova. There is action literally before the player leaves their house, fighting your first pokemon battle in your room and tearing the place apart. The drama builds until the very end of the game, with all of the gym leaders uniting and racing to the pokemon league to aide you, just before you summon the legendary pokemon and duke it in the ruins of the Indigo Plateau in a magic castle as your rival sets his dragon on you.
Sinnoh is mucher quieter, a slower-paced game. Johto and Hoenn are somewhat quiet games as well, but they are very different stylistically to Sinnoh I think. Johto and Hoenn feel very innocent, more pastoral places, and DPPT stand out to me as lacking the intimacy and relationships that Emerald and HGSS have. I compare the Sinnoh games with them because these are the games that they are sandwiched in between in chronology. Dawn/Lukas are around doing lab work, Professor Rowan is not really distinct, he just kinda feels like a prof Oak rehash. Nobody has really changed by the end of the story. I didn't walk away feeling I had built the friendships or made the significant exchanges you have with Eusine, Silver or Lance, Steven or Wally, the only exception to that is maybe Cynthia by the time of Platinum. It was wise to increase her role, and have her follow you into the distortion world. She is the one character I really like and without her I would be very, very sad playing through these games.
While I don't think the basic storytelling structure ever falls apart in DPPt the way I felt playing SM, overall Sinnoh strikes me as a place that has a clinical coldness at the core. This may even may be intentional because space, time and the origins of creation are central themes. But as a result I do hit this wall with how much I am able to emotionally connect with the these games. My interest finally piques at the Distortion World in Platinum, yet this is interestingly still a continuation of the dark, cool, isolated tone that I think is really built into this game. It sure is cool-looking and a fun maze to wander, but you are essentially still floating around out in space.
None of these gym or elite four leaders are too memorable except maybe for Volkner at the end, and he is remembered by me primarily as interesting because he is aloof and feels down and disconnected from his experience. He matches the world he is when I think about.
What Cyrus wanted as a villain is a little opague to me even by pokemon standards, he wants a world without spirit. That makes gameplay feel more detached and vague. I am not really sure why he would want this, but whatever, if that is his motivation then I think Sinnoh definitely should be a warmer, more emotional place to contrast what the world look like without expression. Good battle theme though Cyrus.
The only character who acts really demonstrative is Barry, and not in a good way. Sorry guys, I know a lot of people like Barry, but all of that zipping around I just found annoying. If he seemed to be deeply caring genuinely then it may have worked better as counterbalance to Sinnoh's cool veneer and bleaker stone, but this guy just feels like such a forced, cartoony character that nobody would like that one look at him almost could explain why Cyrus wants to destroy the world. XY rivals take some heat, but I don't remember anyone in a prominent role who was acting like this.
Like I said, Sinnoh is not without good points. I think its okay. It has some good pokemon, Cynthia and interesting environments and ideas, but overall I think Heart Gold and Silver significantly strengthened the 4th gen as a whole, without them I'd be looking at C for a Gen 4 if I were to grade the generation. Since we have the Johto remakes that I think deserve an A+ I would average them together and give gen 4 a B+ overall