I'm not 94dgrif, but since I skipped Ripples multiple times for the same reason (before I ran out of more-interesting-looking VNs and actually gave it a chance and realized how good it actually is), I thought I'd add my 2 cents and people can upvote/downvote me depending on whether they agree or not.
In my personal opinion, the generic bright blue-pinkish background fails to convey that that the main plot is actually rather deep and dark, and two girls touching each other may also give the (wrong) impression that this is at least to a degree a yuri VN or something, which some people have some adversity towards.
Not saying you should outright copy its style, but: in terms of 'vibe', something in the approximate direction of the Eternum thumbnail would represent this VN better, I think.
Something a bit darker. Maybe give more emphasis on the 'ripples' effect, too, make it a little more distorted or something, to give a slightly better hint that this isn't just a fluffy slice-of-life story.
The current thumbnail simply makes one think this would be a much shallower work than it actually is.
Maybe make 2 or 3 new thumb concepts and put them up on your discord or patreon to vote on (and include 'keep current thumbnail' as vote option just in case, but as long as you manage to come up with something cool, I'm pretty sure the old thumbnail will lose the vote).
Oh, and you should absolutely insert the keyword 'harem' in the tagline, too.
Like "Story-focused adult harem sci-fi game".
People might fail to realize it's a harem VN unless they actually go to this page, which they may not even bother to do without any indicator of this from the tagline.
I hope this was of some use :)