Two/optional protagonist means double work in rendering and coding, when many will ultimately play only one MC; which means longer development time, and people having to wait longer to play their preferred MC. Even if you update both MC paths simultaneously with each update, you'll still have lesser content to show for each MC, if you're trying for a reasonable update schedule and size. This seems like a interesting concept, but you need to show people something good, in a tighter schedule, if you want to gain relevancy and stay relevant.
If you're VN is exceptional right from the start, it will leave a lasting impression and people will flock to support you. Plus, they will generally tolerate longer update schedules (as long as the VN gets sizeable & consistently good updates). VNs like Power Vacuum, Artemis, Radiant, Leap of Faith, Intertwined, Summer Scent among other popular titles, have long update cycles, but their updates are big in size and always deliver. If you're starting off with a small demo, you should focus on updating your VN regularly and more frequently, to be able gain a foothold. VNs and Adult games get updated daily on this site, so you need to start off with a bang, or smaller more frequent sparks, in order to light that fire in potential fans and supporters.
I'm not telling you how to do your job, merely giving suggestions and advice based on my lengthy experience with Adult VNs and this site as a whole. Way too many projects get abandoned in their infancy because: the devs were unable to garner support fast enough, or their game remained irrelevant, or they lost motivation due to unfair & harsh criticism, or they got burned out. Regardless, there are more reasons for devs to quit and abandon their projects, than to keep fighting on and developing. The key is in managing expectations, being honest & consistent, filtering through feedback/criticism/negativity, and delivering a great product. If you're passionate in your work, and you do it well, support and fans will automatically flock to you.
On this site, people can be quite immature, ignorant and toxic towards other people's kinks and subsequently those tags that show up in prospective games. I mean I hate NTR too, but if I see a game with it I just click ignore and move on. If it's not for me it's for someone else; I wish everyone did the same, then there'd be no infighting. Even in this thread, there are some people offended by the mere thought of the other MC getting with the same LIs in an alternate playthrough, it's preposterously idiotic! Please don't be discouraged with such comments, just make the game you want to, tell the story you want to tell; if it's good, people will come and cum. Chalk it all up to internet stupidity.
Renders look good, models look excellent, love the incest genre as always. Will wait a few updates to try this, as I never play demos/first versions unless they're considerably big in size; I like some meat on my women and my adult games. Wish you the best of luck in your endeavours,
MaDDoG1111! Hope you don't get discouraged by the negativity on this site!