Just recently getting into the Neptunia series after buying the bundle on a steam sale back in 2018, I could say I have become a fan and cannot wait to play the other titles.
Neptunia Re;birth 1 is a very lighthearted, comedic, and cute turn based JRPG with a well written story that is told through a traditional visual novel style. You follow the adventures of Neptune, a CPU (in this universe, a goddess) of the nation of Planeptune and her friends she meets along the way. The game features and entirely female party where each character is based off a game, game console, or game company. Everything in this game is a reference or homage to the game industry (which is also the name of the world the game takes place in).
The game is a turn based JRPG but does not play like a traditional turn based JRPG. To elaborate, when you enter a battle there is a small ring which is where you can move party, and there is also a blue box on the ground that shows where and what your attacks will hit, this makes for very versatile turn-based combat. There is also a system called EXE Guage that builds up by the amount of hits your party deals on an enemy and how much an enemy’s attack lands on you. Upon reaching 1 bar in the EXE gauge, you can unleash an ultimate attack that each has very eye-catching animations for going ham on an enemy. Through my journey unlike in most other JRPGs where after a certain point most items are useless, that is not the case here in Neptunia. Items will be your best friend throughout most of the game. I cannot recall a boss where I did not use a portion of sorts. The game is also NOT open world, everyplace you adventure to is a small dungeon with quite a lot of monsters and usually one or two strong monster which is an optional mini boss that you must slay for guild quests. Although the game only has dungeons each dungeon is fun to explore, item search, and fight the monsters that are unique to said dungeon. The one flaw that is a turn-off for many newcomers (like me) is the game has way too much grinding for each boss. I got through the huge level spike bosses by means which I cannot discuss in this review.
You can pick the game up on Steam and Ps Vita (but I don’t know why you would). There is also a remake coming soon for PS5 exclusively called Neptunia ReVerse which I would recommend picking up if you have your hands on a PS5.

(SO CLOSE TO THE END I'M ON THE LAST BOSS FIGHT WHY GOD)

Series review:
Re;Birth onwards are polished games, but they are very repetitive and share assets, and like Lego games they only make massive jumps in specific entries.
However the casual moment to moment JRPG gameplay is fun, and the characters only get better the more games you've played. NEPU NEPU

Pros:
Fun gameplay
Decent enough story
Good characters
The dub is great
The plan system is cool
Cons:
Difficulty spikes
Permanently missable content that'll make it 10x harder to grind
Not much enemy variety
way too much DLC (including the only other good healer in the game aside from Compa apparently)
Characters will be removed from your party for a bit and iirc you won't get back any items you gave them

Actually a slightly better first impression to the Neptunia series proper than I was expecting. The positioning and combo-oriented turn based combat is fun and is surprisingly strategic at times, the soundtrack and sound design are good and the game has a noticeably good english dub. Overall I had a pretty fun time with re;birth1 and the game didn't feel like it overstayed its welcome either, taking about 21 hours to complete.

Unfortunately rebirth is also held back by a grindy game structure, literally recycled dungeons, enemies and bosses as well as character abilities just being completely unbalanced. Magic attacks feel useless in this game (at least in my experience) and I got through most fights just by spamming physical combos and Exe moves.

the nep series is definitely something you play more for the "plot" rather than the actual gameplay, especially when they reuse shit constantly throughout the series. Really REALLY standard ass JRPG in terms of gameplay, and this installment really doesn't have much going for it in terms of its plot. Pretty standard "beat the bad guy" story with a bunch of video game theming, and an incredibly quirky localization. If you like moe girls and video game history then like you will probably find one aspect of the game that you enjoy, but if those two things dont do anything for you ur gonna be turbo bored and probably uncomfortable. I eat this shit up though, so this was actually the start of me going through the whole goddamn franchise. If you wanna start here this games been remade twice already so probably play one of those instead but I wouldn't know.