Cyberdimension Neptunia: 4 Goddesses Online is an Action RPG featuring the Neptunia cast as they play as themselves in an MMO. The sixth Spin-Off game of the series (the fourth spin-off title to be developed by Tamsoft), and the second title of the franchise to be developed for the PlayStation 4. Notably, this is the first game to be using the Unreal 4 engine, thus boasting a significant visual difference to its predecessors.
The game's premise is that the world of Gamindustri is relatively peaceful after being saved numerous times by the goddesses and their friends. During this time of peace, the four goddesses of Gamindustri have been invited to participate as beta testers in the popular MMORPG Four Goddesses Online, where they themselves are actually featured as official character models.
The MMO takes place in a fantasy setting known as Asgard, with the towering World Tree being most notable landmark in the world. And as the four first log in they are greeted by the game's guardian character responsible for advising new players, Bouquet. Learning from her that they are supposedly the "Chosen Ones", and that the world of Asgard is in danger from the Demon Lord.
To save the world, encounter their other selves, make new friends, and get little sisters, filled with thoughts in their hearts, the goddesses will step foot into the Cyber Dimension.
Cyber Dimension Neptune provides examples of:
- Absurdly High Level Cap: You can build your characters up to Level 200. Assuming no excessive level grinding, you'll probably be about Level 50 by the game's midpoint.
- Action Bomb: Mandrakes and other variants bury themselves in the ground, waiting for a chance to ambush their victims and blow up on them. Although they cannot be harmed when embedded underground, they can easily be disarmed by killing them before they reach their targets, because of their minuscule health.
- Action Girl: As always, the main cast consists entirely of ass-kicking girls.
- Anti-Frustration Features: If you bite it during a story boss battle and return to the dungeon, you'll start right at the fight instead of wading through the dungeon again.
- Badass Adorable: It's always applied to this series, but Ram and Rom especially so who have switched from mini mages, to a ninja and a samurai respectively.
- Bloodless Carnage: Much like previous games, there is no blood in this title, but it makes more sense since this one is set in an MMO.
- Brick Joke: Bouquet is a young sister candidate designed by Rina Sato, Vert's voice actress, who idolizes Vert and wants to be her little sister. Yes, Vert clearly gave up waiting for Microsoft, and just designed her own little sister!
- Any time a spin-off game is based round one particular character, they end up getting the Butt-Monkey status. This game is based around Vert's favourite game, includes a character designed by Vert, but she seemingly deliberately made sure that she avoided it being based round her for that very reason.
- The Cameo: The pre-release promotion in form of forum posts by in-game characters have cameo from characters from other Neptunia games that aren't present in final product like Ran-Ran, The 4 Oracles, Rei, Linda, The Gold Thirds, Umio, and, of all people, Setag (although Setag seems to get Canon Immigrant treatment, since she actually gets a voiced line in-game).
- Debug Room: The Unreal World dungeon is in-game version of this. Funnily enough, if you turn the camera around at the start of the dungeon, you can see it has Unreal Engine 4 logo on it.
- Deep-Immersion Gaming: Everyone's in-game avatars look just like them.
- Equipment Upgrade: A first for the series and very important here, as new weapons and armor increase in stats very slowly, so upping their power is necessary to stay in good condition.
- Expy: The beta testers Kiria and ✝Kuronekohime✝ are ones to Kuro and Kuroyukihime. Fitting, since Dengekiko makes an appearance here as well.
- Fake-Out Fade-Out: Gloriously. After the end credits roll, Neptune abruptly arrives, tells the player that it only seemed like it was over, but there's so much more to do, and the plot resumes.
- G.I.R.L.: Since this game is set in an MMO, this got referenced quite a bit. The biggest thing is that most other players (who aren't personal acquaintances) thought all the CPUs and Candidates are just random players who use their avatar and not the actual CPUs using their own likeness as avatar in-game. It doesn't help that there are other players who did use their likeness in-game. This ends up shocking the GM when she learns that the CPUs are actual CPUs and not just random player when they contact her outside of the game to offer help with game problems.
- Hollywood Hacking: There's a competition between hac sorry, crackers within the game, and it's treated more like a game of Duel Monsters from Yu-Gi-Oh! than anything else. In other words: cracking is essentially a children's card game.
- Kill It with Ice: Ice based attacks are generally effective against undead enemies as it is the only element they are weak to.
- Game Within a Game: Four Goddesses Online, the focus of this title.
- Mundane Made Awesome: While there are shows that show Dueling Hackers having intense battles, this game amps it up and treating it like a JRPG battle, complete with Calling Your Attacks and special effects.
- Panty Shot: Lampshaded by Neptune when she specifically mentions Vert is wearing a leotard under her skirt so she won't be able to provide any in this game.
- In one side event, Neptune discovers that she can adjust the camera angle in the game to provide these, complete with an accompanying CG. When Bouquet is asked whether the feature was deliberately added, she comes up with a speech restriction.
- Show Within a Show: Again, Four Goddesses Online.
- Stripperific: Vert and Uni's outfits look to be more form than function. Justified as the game is itself a fictional MMO - there's no reason for form and function to correlate.
- Talking to Himself: In-Universe. The titular Four Goddesses are sophisticated AIs based on the appearance, personality, and voiceprints of the four CPUs - i.e. half the existing player party. The characters have a field day with this.
- Thanking the Viewer: With almost literally everyone.
- We Cannot Go On Without You: If the character you're controlling is defeated, you'll be sent back to town shortly after.