Guild Wars had the feature of allowing to set a secondary language. This would translate all game text from the main language into the secondary one in real time as long as you hold the given key down. This meant that at any point, you didn't need to fetch a dictionary or translate a word, wasting time and immersion. I'm so sad I haven't found any other game with this feature.

I'm trying to play games with another language, and while sometimes it's ok, other times you really need to know the language to understand how understand mechanics that are introduced into the game. City Skylines was a super tough game to play in a learning language, but it would have been a nice learning exercise if I had the above feature.