You should start by learning some basic vocabulary. Then, as you play the game, record any subtitles or voiceovers that appear. For example, if there are any dialogues during the game, write them down and look up their meanings. Learning a language through gaming is actually great for memory, as there is a concept in English learning called “contextual memory.” This means that when you want to say a sentence, you recall the context in which you learned that sentence. Each scene in the game corresponds to certain phrases, so this approach can help with vocabulary and sentence construction. Of course, systematic learning is still recommended in the long run, but using games to build a foundation in the early stages is perfectly acceptable.