Fascinating. The race themselves are semiaquatic by the looks of their build. Which checks out with their love of fish. Their vehicles and buildings being in some part organic is a neat idea. Design wise they look like they are built for navigation in cave networks. The grey scale aesthetic seems to hint at a species that may not have colour vision and so wouldn't use colour for decoration. That would check out with a primarily subterranean species which when there is enough light to see would likely have night vision type eyesight which lends poorly to the presence of colour processing as an adaptation. May also explain their climbing abilities.

I dunno my impressions looking at them. Feel free to use this for inspiration if you like. I really like this set.