The SEQUEL series is probably up there as one of the top indie JRPGs. Not JRPG H-games mind you, but JRPGs as a whole. The sheer quality and continuous improvements in all aspects: equipment, exploration, skill building, combat, etc, throughout successive games of the series is astounding. It streamlines clunky mechanics of old games but doesn't over-simplify them. Its battles include a bit of a puzzle aspect to them where you have to figure out when to best use your skills to stop dangerous moves since some have long cooldowns, all the while maintaining your damage, healing, and buffs/debuffs as with any other turn-based combat game. All bosses have a set rotation so you're always learning with every attempt and rarely RNG-dunked.