Hi Yanazake, are you a dev with this game?
I might have anticipated that the demo game would be complete enough to run without installing a 3rd party ROM emulator (for which is how I'd assume the TANGLEWD.BIN file in this itch.io repository to be).
I see that you're saying that it' not about the code in
./linux/tanglewd_64
but the way that Unity refers to .so files on the user's system?
And while it is possible to include .so files with the game itself, in this instance for some opaque reason the file is being scanned on the user's computer?
... for a game installation, I find that very strange. Isn't the point of a game package manager like unity to include all the code to make the game run?
hmmm... I did some digging on this.
I see people writing in different parts of the internet to use a PPA. And I'll tell anyone here listening -- one VERY important lesson: NEVER run a PPA for a piece of code from a source you do not personally trust such as a close friend or coworker.
People will tell you "you need to run this to get this other thing to work" -- and "look here's the source, see? it's fine!" And if you accept the PPA, you also accept all updates for that piece of code. That's what package management is after all; but since it's a PPA, updates aren't part of a repository's web of trust that can veto bad actors. The first update can be benign, and the second one, but a third update can contain a hidden payload from the source who's a black hat in disguise. There's no possible way you can remain vigilant all the time.
Some good news, though: I found a reference to a Debian package at
dpkg-deb --info libpng12-0_1.2.54-1ubuntu1_amd64.deb
^worth checking out what the repository has to say before thinking of installing it.
However I run arch on this laptop, so my package manager (pacman) returns no such libpng12-0 package or as a file within a package when I search for it.