"One thing we're not too happy about is the way RPGs take 2-3x the resources yet sell about as well as any other game. While we've released some nice ones, and have an amazing game coming out soon (Seinarukana is nearly read to start promotion on), unless we can see increased interest by fans it'll be hard to choose another one in the near future. "
One issue I can think of is that RPGs require special marketing at a different audience. If you ask VN fans to buy an RPG, they're going to whine that there's gameplay interfering with their story. RPG fans don't necessarily frequent VN sites, because they don't like VNs especially--they like RPGs. On top of that, when RPG fans are looking for RPGs to buy, they're looking for promotional materials that highlight the gameplay: gameplay screenshots, gameplay videos, and playable demos. RPG fans tend to read reviews before they buy, which means you need to get RPG sites to review your games.
I wrote a piece about Yumina the Ethereal detailing my concerns about the marketing. I think you saw it, because some of the concerns were addressed. But I never saw any reviews on RPG sites, which was a big reason it probably didn't do as well as you'd hoped. There's a huge potential audience for VN-style RPGs with strong gameplay, but you're going to have to work a bit harder to tap it than you're probably used to. But if you spend the huge amount of resources to license a long RPG like Seinarukana...why wouldn't you market it the best you could?
The other big thing you HAVE to do with Seinarukana is you have to get it on Steam. Absolutely. Positively. If you can get it on Steam, and you can get it noticed--the game will sell like hotcakes if you price it right. I've played Seinarukana, and the gameplay is a blast. Steam users will eat it up. Censoring the H-content in Seinarukana will be no issue, because there's hardly any to begin with. And with a censored version, sites like RPGFan and RPGamer should review the game, which will multiply your sales. Make sure you get them review copies before release!
Just make sure you throw some marketing muscle behind the game this time, 'kay?