Sinnoh Remakes
Paradox Diamond
Quantum Pearl

They're mostly bad.

Good things
Megas are back. Mega Jynx is real. Mega Infernape looks like Sun Wukong.
Controllable camera in all areas.
All areas are Wild Area like Galar DLC.
All areas have a battle background that matches the scene like in Let's Go. (No white voids)
Paradox Dialga.
Quantum Palkia.
Null Giratina.
??? type Arceus
Ball Seals are back.
Contests are back if that's your thing.
Music is great.
Vs. Seeker is back.
Regigigas and Spiritomb events are great.

Bad things
No Unova, Kalos, or Alola Pokemon in base game.
Following Pokemon limited to Amity Square in the main story and allowed in the Battle Zone post game.
No Battle Frontier just the Battle Tower with the Frontier Brains as NPCs in the tower.
Darkrai and Shaymin events are in the base game. Arceus will be locked behind paid DLC because they technically never released the event the first time.
Charon and the Team Galactic post game is in the paid Arceus DLC now instead of taking place in Stark Mountain.
Underground is now a Festival Plaza style hub for online battles and multiplayer minigames like mining, capture the flag, and raid battles against Mega Pokemon. You can still build a secret base though at least.
Villa area gets the ORAS "coming soon" treatment. It's not even planned for DLC.
Forced EXP share still here.
Game is overall easier.
Makes Sun and Moon feel like a short film in terms of cutscenes.
Sword and Shield Battle Timer still here.
No graphical or animation improvements.