DS Fanboy pal Zachary Hinchliffe is powerfully awesome, and you can quote us on that. He's working with Croik of the Phoenix Wright fansite Court Records to translate the Japanese Gyakuten Saiban 4 Flash demo, which actually consists of part of the first case.
It's in a very early stage right now-- essentially, once you get past the intro and into gameplay, the text switches over to question-mark speak that is even less useful than the original Japanese dialogue, but you can at least watch the introduction. And you can set your bookmark now to play more as more gets translated, because we're sure you'll get to play this demo to completion in English before the game gets an English release.
