Duh, you're right... in all my thoughts about aesthetics, I failed to realize it's just kana, which is irrelevant to someone that's already an English speaker.
How's this? I originally left the space occupied by the kana empty, but that left a big empty area that was too noticeable, so I figured I'd strech the subtitle to use up all of the alloted space:

EDIT: I'm done translating the 4th game's title screen as well (the 4th game was split into multiple titles for the sake of trading, a la Pokemon):

That's all the GB/GBC titles complete! Hopefully someone will work on these someday.