They’re dungeon crawlers, more so than your average JRPG.
I don’t think there’s any grinding in the games. Mapping out the whole dungeon is a standard for dungeon crawlers, and as long as you do that, it’s all good.
Would suggest Nocturne as well, which is also arguably the best SMT game as well. Introduced the press-turn system that the earlier games lacked, and is stylistically the coolest and most cohesive as well.
DDS games are great, although somewhat more limited in their gameplay with not as much party variety. Story is more narrative heavy and melodramatic, but interesting setting and Kaneko’s designs elevate it way above over typical anime trash.
Kuzunoha games are interesting, but the most rough around the edges as well. The first game ties into earlier SMT games in a really cool way. Setting is very unusual for a JRPG though, so definitely worth a try.
P3&P4 are okay. I regard P3 pretty good, even though this marks the animu creep in the franchise. P4 was more of the same and while most people consider it superior due to pretty superficial improvements and/or subjective plot/style/character preferences, it is personally my least favorite MT game.
Want to get into P1 and P2 games as well, but the original PSX localized version is incomplete, and the PSP remake has godawful music compared to the audiological heaven of the original. P2 is supposedly the best Persona game.