I am a native English speaker, but I study French on the side. One day, I thought to myself, "Why not try playing Pokémon Mystery Dungeon in French?" So I did. I started with Explorers of Sky, and there's not really much to say about it besides practicing reading a foreign language while learning one really helps. When Pokémon Super Mystery Dungeon came out, I lost interest in that playthrough and moved on. While the French Explorers of Sky (Explorateurs du Ciel) was pretty straightforward translation that said more-or-less the same thing as its English counterpart, in Super Mystery Dungeon (Pokémon Méga Donjon Mystère) it's clear that the team took a few liberties... and it worked out great, especially in comparison to the English translation, where at some points there's obvious errors in translation. I'm going to point out a few of my favorite differences, including the English text, the French text, and my best loose translation of the French text back into English (literal translations are hard to read, so oftentimes loose translations are better).
This post contains unmarked spoilers. Stop reading now if you have not played the game and want to avoid spoilers.
1. Realizing you're a child
Nuzleaf: Why, your childish pranks even got me caught up in your mess, I reckon!
Hero: (Childish pranks? Do I look like a child or something to the Pokémon in this world...?)
Pifeuil: Heu là ! Avec tes bêtises, me v'là embringué dans des histoires de gamin !
Héro: (De... de gamin ? Est-ce que je suis un Pokémon enfant, dans ce monde ?)
French -> English
Nuzleaf: Why, your nonsense got me caught up in the business of a child!
Hero: (Of... of a child? Am I a Pokémon child in this world?)
This difference is a minor one, but shows that instead of simply looking like a child, you've become one. Gates to Infinity's English translation did the same thing: you think to yourself about how you look like a Pokemon, rather than thinking how you've become one; however, I don't know off-hand what the French version says.
2. Entering Foreboding Forest
Pancham: [To hero] Where'd you come from? You're not from the village.
Pancham: What's the matter? Skitty got your tongue?
Shelmet: Well, no one's gonna understand you if you don't ever speak up.
Pandespiègle: D'où tu sors ? T'es pas un gamin du village, ça c'est sûr.
Pandespiègle: ... Bah alors ? T'as perdu ta langue ?
Escargaume: Tu sais, y'a un truc qu s'appelle « communiquer ». C'est pratique.
French -> English
Pancham: Where did you come from? You're not a child from the village, that's for sure.
Pancham: ... So? Have you lost your tongue?
Shelmet: You know, there's this thing called "communication". It's useful.
It took an extra few months for the European version to be released, presumably to perfect the non-English translations. I say it certainly shows with things like this.
3. School Life: Evolution
Audino: All right, children! It's time for health class.
Audino: Today we will be learning about evolving.
Shelmet: What? Evolution?!
Partner: Isn't that, like, maturing quickly?
Pancham: What are you talking about? Don't you know what Evolution is?
Pancham: Evolving just means that you get bigger. I for one want to get bigger.
Audino: Well... That's one way to sum it up, yes.
Goomy: What? We'll get bigger?!
Audino: It's not only your bodies growing larger, though. It causes many other changes.
Audino: Evolving does bring you closer to being an adult... so in that sense...
Audino: [Partner]'s assumptions are not entirely off base.
Deerling: (What's that supposed to mean?)
Nanméouïe : C'est l'heure du cours de sciences !
Nanméouïe : Aujourd'hui, les enfants, je vais vous parler de l'évolution.
Escargaume: Lévo... l'évolu-quoi ?
La Partenaire: L'ébullition ? Genre quand ça bout et qu'il y a des bulles ?
Pandespiégle: Pfff, n'importe quoi ! T'es complètement à l'ouest !
Pandespiègle: L'évolution, c'est quand tu deviens un grand Pokémon balèze ! Ça me fait trop envie !
Nanméouïe: Hé bien... oui, on peut voir ça comme ça.
Mucuscule: C'est vrai, on peut devenir plus grand ?
Nanméouïe: Oui, sauf que l'évolution ne concerne pas que la taille, mais aussi bien d'autres aspects.
Nanméouïe: Elle permet en quelque sorte de devenir adulte... Votre corps bouillonne...
Nanméouïe: [La Partenaire] n'avait pas tout à fait tort en parlant d'ébullition, en fait !
Vivaldaim: (Je ne vois pas trop le rapport, mais si Madame Nanméouïe le dit...)
French -> English
Audino: It's time for science class!
Audino: Today, children, we're going to talk about evolution.
Shelmet: Evo... evolu-what?
The Partner: Boiling? Like when it boils and there's bubbles? [Note: the difference between the words for "boiling" and "evolution" is the same as the difference between "b" and "v"]
Pancham: Pfff, whatever! That's completely wrong!
Pancham: Evolution, that's when you become a big strong Pokémon. That makes me want to evolve too!
Audino: Well, yes. One could see it like that.
Goomy: That's true, you can become bigger?
Audino: Yes, except evolution is not just about size, but also a bunch of other aspects.
Audino: It allows you in some way to become an adult... your body boiling/seething...
Audino: [The Partner] is not entirely mistaken when talking about boiling, in fact!
Deerling: (I don't see how that relates, but if Mrs. Audino says so...)
This is probably my favorite. Too bad this joke just doesn't work in English (and that the English translation team missed out on opportunities like this).
4. School Life: The Temperature
[The bell sounds]
Goomy: Phew! I thought today would never end!
Pancham: It's a real drag lately, huh? And it's been so crazy hot all the time.
The Partner: Yeah. When it gets this hot, I feel feverish and my brain gets flunky!
Shelmet: Your brain gets "flunky," huh? More like you're kind of flaky, [Partner]!
Espur: [Partner], I don't think that's the word choice you were going for.
Mucuscule: Pfiouuu, c'est enfin fini !
Pandespiègle: J'suis trop crevé... Vous trouvez pas qu'y fait super chaud ?
La Partenaire: Ouais... Il fait vraiment chaud, c'est la faute du « réchauffage climatique » !
Escargaume: Bouahaha ! Mais quelle gourde ! Elle sait même pas parler correctement !
Espur: Mais non, [Partner], on dit le « réchauffement climatique ».
French -> English
Goomy: Phew, it's finally here! [Summer vacation]
Pancham: I'm so exausted... Do you not find that it's super hot?
The Partner: Yeah, it's really hot; it's the fault of "global reheating"!
Shelmet: Hahaha! What a blockhead! She doesn't even know how to speak correctly!
Espur: No, [Partner], it's called "global warming".
As an inexperienced French reader, this is the same kind of mistake I'd probably make. Note the difference in the suffix of "réchauffage" and "réchauffement". "-age" is more in the context of cooking, while "-ment" is what she meant. Also, in case you didn't know, the French translation assumes the player to be male and the partner to be female (hence Shelmet referring to the partner as "she"). This is because there's not that much wiggle room to control what the characters say in response to the gender of the player and partner.
Most of the item names are more-or-less the same in both languages. A few of the emera's stand out.
The Type Bulldozer is an "Ignore-Type", which doesn't sound as cool in my opinion. They make up for it by making the Toughness Emera the "Esprit Tenace", or Tenacious Spirit, which is way cooler.
There's various other differences, but these stood out to me. Overall, both translations do the game justice, and the partner is just as adorable in both. ("[Hero]! Good mor-ning!" and "Ohé, [Héro] ! Coucooou !").
Hopefully this was an interesting read. If anyone who's more experienced in French found I made any mistakes in the translations, feel free to let me know.
[Upon learning the Nexus is destroyed regularly] English: "(From what I saw yesterday, I can imagine...)", French: "(Eh ben, la vie n'est pas facile pour ce pauvre Pilier Atlas...)", French->English: "(Oh, well, life is not easy for the poor Pokémon Nexus)".