Well think of the most popular games: SS, FET, Milfy City, Monster Girl Island, etc which are harem and really they dont push the envelope fetish wise (Well I guess Eve being a trap is one which was quite controversial and it was added until this late in the game when it had already built its fanbase through tame content) so really a bunch of fetishes wont really factor. I mean even though Seeds of Chaos has one of the best devs regarding work ethics and being one of the original wegs, It had the slowest growth out of all of its peers and that game has nearly every fetish imaginable which would had given it bigger support if the theory of many fetishes giving it more support held true. But really the issue is that these games must give content periodically and so if the game lacks focus it wont appeal to anyone if they have to wait several updates waiting for their fetishes to shime in. Again it would be a case of quantity vs quality, if Seeds of Chaos was all about Rowan being a Chad slaying pussy im sure that the game would have easily reached 20k or so long ago.
Still I think that being a harem sci fi game gives it a niche. Not to mention that the artist is relatively popular so I think this game has enough appeal to succeed but it will also need a good release schedule.