There should be another 16-Bit Gem since at the end of the Dragon Quest I & II video he said he will be talking about Dragon Quest III. As for when it will be I would like to know when it will be too since Roo have not been around this site lately, but he did post about To The Moon so hopefully he will be posting more.
From what I remember Roo said he had computer issues on the Echo screen awhile ago. If those computer issues involved a hard drive crash then that would mean he would have to re-record everything he already had recorded, which I know from experience, really sucks. Trying to recapture some bits would be hard to do too since you might have the lingering feeling that it sucks and was better before the crash.
He’s having some personal issues in life too as he’s stated on his twitter. I’m really waiting for his next review too, but it’s best for us to understand his case and cheer him on through all of this.