NISA

AR TONELICO ELEMIA, MANA KHEMIA 1 and 2
o Bad string handling leading to complete crash against specific bosses (AT1, MK2) / major part of the extra dungeon enemies (MK1). MK2's crash is rather easy to avoid, though.
o MK1: Unnecessary and flagrant name changes to a variety of playable main characters.
o MK2: Lack of testing in the extra chapter leads to crashes when doing certain tasks if Ulrika is the main character instead of Raze: Student handbook and Job post usage crash the game.

AR TONELICO METAFALICA
o Typographical errors, missing words, and shaky sentences, mistranslation of important game terms, inconsistently-adapted names
o Localization introduced or exposed game-crashing bugs in the game.
o NISA marketed the game based on Sex Appeal, when, in fact, AT2 was intended to be a more serious and thoughtful game, with less emphasis on cheap hooks and a greater focus on the plot, than Ar Tonelico Elemia
o In order to fit English voice acting onto the disc, they cut approximately half of the Japanese voice-acted scenes, leaving many important plot points lacking appropriate impact.

AR TONELICO QOGA
o Typographical errors and untranslated text in various spots on top of their "translation" not even being remotely close to the japanese track and english voice track, what little there is, not even matching the text in some areas.
o Binary Field (DLC episodes) scam where they put out each chapter separate then a few days after a bundle pack which didn't work if you had downloaded the first episode.

HYPERDIMENSION NEPTUNIA
o Neptunia 1 would crash on the dungeon leaderboard screen if it couldn't upload your score while you were on PSN for whatever reason.

HYPERDMENSION NEPTUNIA mk2
o Very questionable localization quality. (bad translation, unfunny jokes/lines added to several dialogues which changed the characters personalities at times)

HYPERSIMENSION NEPTUNIA V
o Very questionable localization quality. (bad translation, unfunny jokes/lines added to several dialogues which changed the characters personalities at times)
o Didn't tell the gamers idol events DLC would not be included, then, when brought to attention, denied any and all knowledge of such DLC.
o Freezing issues with some DLC.

WITCH AND 100 KNIGHT
o Game-crashing bugs (rumor about a GameFAQs user fixing everything and mailed such solution/file to NISA. Still no official support a year from release, nor token mention of any such thing.)
o PS3 overheating (Confirmed to be replicable by person who originally made the post) http://nisamerica.com/forum/viewtopic.php?f=8&t=14425&start=90

ATELIER ARLAND TRILOGY
o Name changing: Esty Erhart => Esty Dee (S T D = Sexual Transmission Disease, get it? XD)

RHAPSODY DS
o http://www.siliconera.com/2008/10/13/bonus-content-cut-from-rhapsody-ds/
o http://www.siliconera.com/2008/10/14/falling-flat-encountering-rhapsodys-ds-glitches/

DISGAEA 2 PSP
o They fucked up the dlc characters so they don't have voices.
o They decided not to release all the dlc characters, but released the final character, majin hinako.
o Majin hinako unlocks item book collection slots because it assumes you have the other dlc characters.
o Downloading majin hinkao means you can't complete the collection book, effectively killing anyone going for 100%

DISGAEA D2
o Game-crashing SKILLS (several Fire-based)
o OPENING stops abruptly
o Fuuka and Desco were free DLC for the first month after release in Japan and Asia. Day 1 paid DLC in USA and EU.
o CPU melting bug at release

DISGAEA 3
o DLC scam. Purchasing content one by one locks certain content needed for 100% completion. Purchasing as a bundle unlocks it all, for the low price of $50. NISA released vouchers for a limited time as apology.

MUGEN SOULS
o Scrubbing minigame removed over 120 CGs removed. Basically censored extremely lazily. Excuses given over the years were many and varied, but some of them were "We wanted to appeal as much as possible to a wider demographic." "The vocal minority can't put a dent in our wallet." "We find this content creepy." "Unofficial ESRB rep indicated this title has potential for AO (it didn't)" "We found this content distasteful, so you don't want it anyways."
o Created new bugs and glitches not seen in the JP release
o Massive lag during regular battles
o Can fail an area load after a battle forcing you to restart from your previous save
o Released an LE which had bath sponges and a towel even though the bath minigame was removed which was a massive slap to the face which the LE sold poorly(still have copies of the LE on their site).

MUGEN SOULS Z
o Scrubbing minigame removed, over 120 CGs removed. See entry for Mugen Souls
o Elka introduced as the Hero of Water World when she's the hero of the Fire World
o Slumbering Boss battles cause freezes in Mugen Field (Note: this has been patched as of July 2014)

NATURAL DOCTRINE
o Ending is not subbed when using Japanese. When someone asked about this, they were told to use the English dub instead

PSTV
o Won't patch their Vita games for PSTV support, usually defers to Sony despite it being on them. http://nisamerica.com/forum/viewtopic.php?f=8&t=15423#p836008

CRIMINAL GIRLS INVITATION
o Censored the Punishment Time minigame which has pink fog for every level of each minigame(Never goes away). JP version the pink fog goes away on later levels.
o Removed the voices for the punishment minigames.
o Shoddy translation. Changed "Punishment Time" to "Motivation Time" for the punishment minigame and made the dialogue less lewd.

DANGANRONPA: TRIGGER HAPPY HAVOC
o Various text wrapping, spelling and grammatical issues
o Bug that crashes the game when loading a School Mode save
o Made a scene where a character reveals his true gender to the protag less ambiguous and essentially censored it by changing a line stating that the character put the protag's hand on "her body" to "her chest"

DANGANRONPA 2: GOODBYE DESPAIR
o Text wrapping issues
o "jump hitboxes not working (I'll land on top of somebody directly, but i'll just go through them and sometimes take damage)"
o Various images appear in Japanese when the voices are set to Japanese

OPERATION ABYSS: NEW TOKYO LEGACY
o English dub only, no Japanese audio track. When asked why, NISA said it was because there wasn't enough space on the vita cartridge for it despite the entire game being less than 1.5 GB (vita cartridges can hold up to 4 GB)

FAIRY FENCER F
o Changed character names in the english localization (ex. Alyn to Eryn) due to the translator not liking the way they sounded.

DISGAEA 4 (VITA)
o Bacial with the youngster voice has an english line that will crash the game. friend or foe can crash your game. This can be avoided by playing with japanese voices.

MISC
o Localizers have admitted that they do in fact add things to the script just for the sake of "flavor" http://www.siliconera.com/2010/04/29/nis-america-answer-your-trinity-universe-questions-part-2/#DvhRIbzo9JP9x19t.99