They definitely did the katakana talk thing a lot haha. The character names and stuff were especially interesting and often relevant to how they talked - I remember one character was named like 俺の女の子 or something like that, and she kept saying 俺のさぁ as a filler even though she was like one of the tiny little girl npcs. There were definitely some weird regional dialects, the kid with the lisp kept saying like でしゅ, and other just weird stuff like that - I’m sure I missed a lot of the more niche nuances cuz of lack of fluency lol. One thing over the english version though, is that all the text would fit on one screen - I know in the english the sentences would sometimes get cut off and have to continue, so at the least its easier to read in that way.
Oh yeah, the way Stan talked also most notably was quite strange - he used あまり in not negative ways a lot for example. The princess also used like a weird pronoun わらわ, but the rest of her speech wasn’t tooo out of the ordinary.
I might watch a playthrough in english eventually as well to see the differences.
I don’t necessarily like the lack of kanji like others have mentioned, but it’s good practice for remembering readings and learning cute little slang and contractions, and reading quickly!