Nana puts in over 40 hours of work a week and always downplays it as just doing what he likes, suggesting he doesn't see what he's doing as real work. This is probably heightened by all the support he receives from ci-en. Still, from the conversations I've had with him, he isn't overdoing it.
I figure it's okay to talk about this, but when I first discussed R-18's vore content, Nana said there were plans to add vore scenes for regular enemies. When I asked for details, he said he was considering adding a frog or snake girl if possible. The new stage seems to fulfill this idea while reducing the amount of work needed. The lizard girl is very cute, so I'm glad she'll get a vore scene. I like how this is shaping up more than new enemies, though of course both would be nice. But that probably won't happen.
I'm not going into details, but Nana still has plenty to do after this, including even more vore content. I discussed my request with him a lot yesterday and today, it may get featured soonish. For now, Nana has to work out the stage design. He hasn't even decided on the stage #.
About D-gate/Camel's art, he posts it on his blog. He has a number of other shrinking related drawings there, including a succubus-type girl that eats Youki with her tail. Whether such an enemy will appear remains to be seen, but the stage is his idea. I don't really like the idea of another stage without a boss.