Is this game "simple" to play? I mean for someone who has only played Final Fantasies and Dragon Quest-games.
As someone whose turn based RPG experience was like you (Only SE games), i just will complete with some pointers what the others already said.
The battle system is a little more interesting, the first time i played Persona 3 on normal was like someone threw cold water on me.
-> Debuffs and buffs are very handy, be at normal enemies be at bosses.
-> Status ailments can be life saving too, the spell that charms all enemies + charm boost (+ chances of charming) = seeing the enemies beating each until death. Saving a lot of SP.
-> SP. Its the "MP" of SMT, when you enter a dungeon all your allies be 100% healed, and you can be at the dungeon for as long as you want.... this mean you will be at the dungeon as long you will have SP.
The rest you will discover naturally when you play it. Just think that instead of over powering everything with your strongest spells you can play smarter in this game.