Bouhou Youyoumu is a Metroidvania-esque fangame by the doujin circle Marokaka. I made an English patch for it with some technical help from brliron so I'm sharing it here.
If you need the game itself, you can purchase it
here on DLSite.
The first game in the Bouhou series, Bouhou Koumakyou, already has an English patch (though the translation itself is of somewhat questionable quality from what I've seen). I have the groundwork already sorted out for Bouhou Koumakyou 2, the last game in the series, so I'll be doing a patch for it at one point in the future.
You can download the English patch itself
here.