>>715188118FFX perfected turn based combat
you have 3 actives characters with infinite character swaps that don't take up turns. this is encouraged through XP gain.
you have a timeline that is affected by agility + speed affecting abilities during turns.
status effects matter, even and especially in boss fights. blinding bosses that hit hard, casting reflect on bosses that self heal or reflecting their strong spells back to them, then bouncing your own spells off of team mates etc. haste and slow are huge especially in boss fights too.
you have so many ways to customize your party with equipment abilities and equipment crafting.
rikku not only lets you break the game in fun ways but she encourages you to use further systems like the overdrive acquisition system, the steal and bribe system, etc.
overkills let you get more rewards and actually make it worth overkilling enemies for once (it feels like a waste of resources in other games so you just save harder hitting stuff for tough bosses only)
the sphere grid allows you to not only heavily customize your party but also allows you to straight up play the whole game at starting stats which works well because the game has so many ways you can play it that there's always a way to win. like using stone touch on tough opponents or kimahri's blue mage stone breath, etc.
then you got stuff like aeon raising to customize your aeons into long term relevant party members.
the game has a LOT of depth and while not brutally hard or anything, has enough challenge in it to make it satisfying to use everything available to you.
games like FFXIII play faster but are shallow as a puddle in comparison.