7.8 out of 10, too much water.
Okay okay, sorry.
Really, this is a good game, but moreso for its story, art, and references.
Note that this review contains mild spoilers for the game, but nothing too crazy.
Gameplay wise your gameplan stays consistent throughout the entire game with the only thing changing being what elemental stick you beat the enemy to death with.
Fanservice is INCREDIBLY useful and very few bosses even bother trying to mitigate it.
Theres not really any aspect of overworld resource management due to Ancient Reaper, either.
Once you get access to Rushia Gem, you win. Thats it, you just win, final boss? Nothing, you MIGHT struggle with the postgame fights, but by that point you have better Gems available.
Most other pre-Postgame Gems aren't worth considering, they mainly provide gimmicky buffs that you don't really need, Marine Gem is a must since even with it you'll feel like you are on a heavy budget, otherwise MAYBE Korone Gem for the free heals but thats about it. Avoid Aki Gem. Its useless.
For anyone reading this, heres a tip, the final postgame boss is rather weak, but their minions are comically strong, so aim to take them out first.