I'm so happy you like the shaders; they took a while to get just right – I'm planning on releasing the shaders because as far as I can tell, they do a few things more effectively and efficiently than anything else out there~ (If you're interested, it's actually a post effect that I also want to reimplement as a surface shader at some point, to allow different objects to have different palettes – sticking to the four-colours-per-ditherpattern, though :)
I hadn't even considered stuff to interact with in the ship while it's travelling, that's such a great idea – it actually currently has to be slow because everything gets loaded in the background while you travel and it barely loads in time; sometimes, if you go from one planet to a different one that's really close by, you can actually see it load in the surface!
I would've liked for every single planet type to have artifacts/souvenirs as well, and I was toying around with the idea of the probe sending back a "postcard" of sorts from the surface of each planet~
Thank you for your kind words~ they really make me happy and keep the developer in me wanting to make more :3