Lately I play games for two reasons at once: because I want to, and because they’re the best Japanese textbook I’ve found. Everything below was played in Japanese. Some of them made that easy. Some of them made me earn it.
Final Fantasy Resonance (demo)

35.8 hours in a demo that’s supposed to take three to five.
That number says most of what I need to say. Final Fantasy V is my favorite in the series, so this one hit me right in the nostalgia: pixel art done in that HD-2D style, turn-based battles, crystals in danger. It felt like coming home.

It also felt like homework. The Japanese in Resonance is grand and old-fashioned in the way fantasy dialogue loves to be. Summons are called with incantations that no one would ever say out loud in real life. Knights lower their own speech while elevating each other’s in the same scene. Words like 幻獣 (phantom beast) and 飛空艇 (airship) turn out to be Final Fantasy’s own vocabulary, not everyday Japanese. I learned a lot, but I spent a good part of those 35 hours in the dictionary instead of in battles.

So I’m holding off on the full game for now. Not because I didn’t enjoy it, but because at my level it’s more study than play. It’s on the list for when my Japanese catches up to it.
Palworld

561 hours. 52 of 75 achievements.
This was the sleeper hit. I didn’t expect to put over 500 hours into anything, let alone this. It’s the game I thought Pokémon would eventually turn into: catch creatures, then put them to work building your base, mining, logging and hauling while you go exploring.

It’s also where I go when I need a break from studying. The Japanese is mostly short menu labels, so I can just play. Somehow, though, I still learn: 伐採 (logging), 採掘 (mining), 運搬 (hauling), 拠点 (base). Hundreds of hours of seeing the same words on screen does quietly what flashcards try to do.

Shin chan: Shiro and the Coal Town

25.1 hours, and only 3 of 44 achievements, which tells you how slowly I’m taking it.
I love Shin-chan, and getting to play as him is just fun. But this one is text-heavy, so I can only play it now and then, when I have the energy to read.

The payoff is Japanese you won’t find in any textbook: rough, blunt, working-class speech, like 食いてえ instead of 食べたい, and a tough shopkeeper who calls herself あたい. It’s the Japanese people actually talk in, and nowhere else I study gives me that.

Dragon Quest Monsters: The Withered World (demo)

20.9 hours.
This is the easiest read of the four, with short sentences and simple words. The catch surprised me: Dragon Quest writes almost everything in hiragana instead of kanji. That sounds easier, but without kanji it’s harder to tell where one word ends and the next begins, and a few times I misread things completely. It turns out kanji aren’t only a hurdle; they also help you parse the sentence.

It’s still the one I’d recommend to anyone starting to play games in Japanese.

What’s next
Dragon Quest has me wanting more of it. I’m thinking about replaying Dragon Quest XI in Japanese, or trying the demo for Dragon Quest VII Reimagined. Either way, the dictionary stays open.