Well, the Japanese name is supposed to be pronounced like ghee-ah-lah-gah (Gyalaga), so I'm guessing as the "ee" (like "bee") was dropped out of the U.S. name, that it should be pronounced like gah-lah-gah, with the first and the last syllable pronounced identically. But I believe that all of us would know which game we are referring to merely by the placement of the sounds of the consonants rather than the pronunciation of the vowels anyway, so it's all good.