I like this game, although its verbosity can be quite annoying at times. The thing that really gets on my nerves, though, is seeing things like "nya". "Nya" is not a word in the English language, it is a Japanese word that should ALWAYS be translated into English as "meow," the correct English onomatopoeia for the sound a cat makes. When you translate anything into another language, every single word or phrase that has a direct equivalent in the other language MUST be replaced with said direct equivalent or the translation fails. I have the same problem with things like "hihihi" being used for laughter: "hi" (hī) being always pronounced with the long "i" in English. If I were translating from English to Japanese I wouldn't leave things like "meow" and "hehehe" untranslated so why do so many of these developers leave "nya" and "hihihi" and so many other words untranslated?
I'm sorry but what? Do you understand the concept of languages? Okay sorry, this is coming off more offensive then I wanted, starting over.
I don't know how the concept of a "living language" is taught in your country, but languages are and always have been alive, and they have always merged and combined, I don't know if you are a translator or something as you mentioned translating in your post, but first, this is an informal setting, and second it does what language should do which is communicate an idea, also I have seen "nya" used far more then "meow" lately when being used as onomatopoeia and that is for two reasons, one we are on the internet a place where people have memed animes to oblivion so everyone knows what "nya" is, and two it sounds cuter, so it makes more sense to use when you are trying to convey that something is cute or adorable, also that is an expression of multiculturalism, something that should be appreciated, of course, it could be better, but this is a step in the right direction.
As some final thoughts, the mixture of languages isn't something to be afraid of or appalled by, it is a show of unison, of how we are closer to other cultures, these days we can literally interact with almost the entire world and that is a good thing, and these small combinations are what hopefully will get us closer to a world language one day, now this is me being optimistic of course, so I'll finish this with a question because you actually made me curious, why do you feel that way?
Also so you understand where I'm coming from, I'm a Brazilian, I know that the USA likes to call itself the melting pot of the world, but we are mostly on the same level when it comes to that, and in my language, we have many words that are either adaptation of foreign languages or literally just the words as it is, and I bet that so does your language, just think "Pizza".