Thanks! To respond to your questions - there is a lot indeed. I think the trick was reusing the same techniques I used before (materials, shaders, colours, light setups and much more) from my previous project (https://flat.social - spatial audio and video in 3d, much more complex). I reused a lot of already optimised elements from there and the general look & feel that took me quite a lot of time to arrive at.

Also lots of props to Opus 5.5 - it was incredibly good at getting the right game play feel from the start. Some of the quirks it came up with were actually quite funny (try swimming, it's annoying but cute). Ironically I suggest trying dropping large prompts that might be even slightly too vague. The first version of the pterodactyl was literally me saying something like "let's drop a pterodactyl there guarding an atomic bomb". It came up with a pretty good version of it which then I have later calibrated.

All together, it felt much more like an art direction task than a technical one (and I've been programming since I was 12).