Until a downloadable version is available, it can’t be translated. For now if you have a phone app that can translate live/from pictures it’ll be the best you can do.
The Dev has gone on record to say a downloadable version will come once they’ve made more progress on the game, but until that happens we’ll just have to wait.
Is there any way to play this dev games now?
Gonna guess the answer’s probably no.
The service the games were hosted on shut down in the summer of 2023, and the last comments of any sort from the dev were from months earlier; if I’m reading right, they mentioned that their newer game was lacking in some aspects because they’d started a time-consuming real job.
There is a partial archive of the Niconico games site, but it’s wildly incomplete and the actual archive apparently only contains a portion of the data that was scraped. It’s also a 220GB download without a file list, and warns that even the included items might not be complete or in playable format, so I’m not going to download and search it in the slim chance that a couple of very niche games found their way into it. If you’re desperate enough to dig through it yourself, you can find it by searching ‘Niconico Game Atsumaru’ on archive.org.