I’m sure you’re right about that. But the effort would be much greater. I don’t think anyone would do this voluntarily and without getting paid. But if somebody volunteers, I would also be happy about such an Amiga version.
Turrican (especially Turrican 2) was the flagship game on the Amiga and graphically one of the best on the system. The game has used the Amiga like hardly any other game. It was very unusual.
I think that in reality an Amiga Thimbleweed Park would look even less colorful than my conversions of the screenshots and the single game graphics. For each graphic Photoshop created an optimized palette and converted the image on that base. This will probably not be possible in the finished game. Probably there are further restrictions, because different graphics have to share a palette.
I don’t want to stop anyone from creating a good Amiga conversion. Unfortunately I fear that this will be a hell of a lot of work and due to the system limitations (resolution, colors, RAM and disk space) there will be significant losses in the game.
Something great and possibly less work would be: The game automatically downsamples its graphics in real time to Amiga possibilities. This should be possible on modern PCs. A kind of realtime converter/ emulator built into the game. In this way, completely different versions could be calculated in real time without further effort. For example VGA, CGA, EGA, Atari ST, C64 etc.