Hmm...I would be surprised if a game like that didn't have an option for japanese voiceovers. But then again Bujingai didn't, which was perplexing. I'll have to do some checking up on that. I can usually abide-hell, enjoy!-terrible voice acting, but I'm less tolerant if it comes at the cost of story/characterization.
In other news, Mystical Ninja starring Gatekeep--err, Goemon
has been conqured. The final stretch of the game was awesome. I especially dug when Dancin' and Lily sang "Beautiful, My Stage!".
It's a shame that the game is so short though. You blink and you're 2/3rds through it. But I guess the idea is to always leave you wanting more...