Well....I haven't played Super Mystery Dungeon yet, PMD games are almost always great, and Super Mystery Dungeon in particular is adding a lot of neat features. I wouldn't be out of the line to expect it to be good.
Copy/paste from what I've seen elsewhere:
New features:
-All 720 Pokémon that were officially revealed at the time are present in the game.
-Accessories are now visible on both the player and partner in the overworld and in dungeons.
-As the first entry in the series released during Generation VI, it introduces Mega Evolution and the Fairy type to the series.
-Mega Evolution allows Pokémon to become more powerful, attack multiple enemies, and break down walls.
-The Progress Device allows players to save inside of dungeons.
-Wands, items that can be used multiple times, are introduced.
-The Connection Orb replaces the bulletin boards as the interface for taking jobs. -By completing jobs, clients become friends and connections to more Pokémon appear.
-In addition to returning stores, stores called Hawlucha's Slam School, Café Connection, Klefki's Rockin' Lock, (Japanese: ニャースシアター Meowth Theater), and (Japanese: ラプラス大陸便 Lapras Intercontinental Travel) are available.
-When all team members surround an enemy Pokémon, called an Alliance, moves that would normally be not very effective ignore type matchups.
-Items called looplets and emeras are introduced. By putting emeras into a held looplet, Pokémon can be powered up. Any emera obtained in a dungeon disappear when leaving it.
-A (Japanese: ジュークボックス jukebox) feature allows players to listen to music from the games and even previous titles in the series.
Returning features:
-The Deposit Box once again replaces Kangaskhan Storage.
-The Belly mechanic makes a return.
-The personality test that featured in the first two installments returns; however, it is optional.
I can however personally confirm that the
soundtrack is fantastic.