My native language is Polish, I understand English well and very little of German. When I first saw the title of the game, it felt natural to me to pronounce "Raffe" the way it would rhyme with "cafe" and also say that "e" on the end of "Giraffe" so that it rhymes. Then I checked that "Raffe" is actually German for "I gather" (and is pronounced with loud "e" at the end), which fits the theme of the game. But the publisher is Korean and the author is Japanese, so they may speak German or they may just have felt that repeating the the last syllable of "Giraffe" for the 2nd time would sound cute and been unaware it exists in some language as an independent word. I have no information what the actual intention of the author was for it to be pronounced, so I will just keep pronouncing it the way it sounds nice to me. I think you should also just pick the pronunciation you like most and just go with it.
(By the way, German for "giraffe" is also "Giraffe", so the title could be all in German. In German it's pronounced with loud "e" at the end, so it would authomatically rhyme, but "G" is pronounced differently that in English)
