It's good to know the old www folder worked. I've made a full new download you can try to see if it fixes things. I've changed the file name for the title image again just in case, and it has the new plugins disabled again, as patching plugin changes can be weird sometimes. If that doesn't work, I did also add quite a few new audio files to the game, so it's possible there's some sort of naming issues there. (I would expect that to cause an issue when the audio comes up, rather than on launch, but it's still possible.) So to test that, you could delete the audio folder from the new version inside of the www folder and copy over the old audio folder from 0.58 to see if that fixes things. (If it does, let me know and I'll go double check all the new files and see if there's any obvious naming issues. You'll probably encounter a bug when playing with the old audio if you get somewhere that calls the new audio.)
If neither of those work, my last idea is the fact that I accidentally uploaded version 0.58.4_Linux as a zip rather than a tar file. I would expect that to cause issues, not fix them, but I could try uploading a zip of the newest Linux version if everything else doesn't work.
New download: https://mega.nz/file/FHJDQChC#w6i3zZfb_4k3iXOhXxVRFFZFpLldr8afi_-48Lbnf0s