Ok, so the ECCHINSFW-final.rar file also contains the gallery and some extra content. Both versions are NSFW though, so I don’t get the naming difference? The -final-version also contains the Linux and macOS versions of the game – it’s just tagged wrong (please kindly fix!).
The Linux version is also still missing the executable bits on the Ecchi_Sketch.sh and lib/linux-x86_64/Ecchi_Sketch files, but manually setting them is enough to make it launch; the libssh-gcrypt.so.4 workaround is NOT NEEDED for this version. (Also dealing with .rar-files is annoying, but its not a deal-breaker.)