When trying to run on Ubuntu 19.10, I get a mess of different missing library errors.

./NecroDancer: error while loading shared libraries: libGL.so.1: cannot open shared object file: No such file or directory

I tried to get around it by looking for libGL.so.1 on my machine and symlinking it in /usr/lib, and got:

./NecroDancer: error while loading shared libraries: libGL.so.1: wrong ELF class: ELFCLASS64

Is this game 32-bit? I tried to install 32-bit GL libraries and got another missing library error, for some other library.

I thought I'd played this game on Linux before. Did it break recently? Or has it always been broken on 64-bit machines?

The game is indeed compiled for 32-bit libraries. If you check `ldd Necrodancer` you can see what the game needs. On my Debian system, these are the 32-bit libraries it needs along with the packages that provide them:

```
libgl1:i386: /usr/lib/i386-linux-gnu/libGL.so.1
libopenal1:i386: /usr/lib/i386-linux-gnu/libopenal.so.1
libogg0:i386: /usr/lib/i386-linux-gnu/libogg.so.0
libvorbis0a:i386: /usr/lib/i386-linux-gnu/libvorbis.so.0
libc6:i386: /lib/i386-linux-gnu/libpthread.so.0
libstdc++6:i386: /usr/lib/i386-linux-gnu/libstdc++.so.6
libc6:i386: /lib/i386-linux-gnu/libm.so.6
libgcc1:i386: /lib/i386-linux-gnu/libgcc_s.so.1
libc6:i386: /lib/i386-linux-gnu/libc.so.6
libglx0:i386: /usr/lib/i386-linux-gnu/libGLX.so.0
libglvnd0:i386: /usr/lib/i386-linux-gnu/libGLdispatch.so.0
libc6:i386: /lib/i386-linux-gnu/libdl.so.2
libsndio7.0:i386: /usr/lib/i386-linux-gnu/libsndio.so.7.0
libc6:i386: /lib/i386-linux-gnu/librt.so.1
libatomic1:i386: /usr/lib/i386-linux-gnu/libatomic.so.1
libx11-6:i386: /usr/lib/i386-linux-gnu/libX11.so.6
libxext6:i386: /usr/lib/i386-linux-gnu/libXext.so.6
libasound2:i386: /usr/lib/i386-linux-gnu/libasound.so.2
libbsd0:i386: /usr/lib/i386-linux-gnu/libbsd.so.0
libxcb1:i386: /usr/lib/i386-linux-gnu/libxcb.so.1
libxau6:i386: /usr/lib/i386-linux-gnu/libXau.so.6
libxdmcp6:i386: /usr/lib/i386-linux-gnu/libXdmcp.so.6
```

The game also ships with one pre-compiled 32-bit library that wasn't found in my system libraries, libglfw.so.2, but that one's handled by the LD_LIBRARY_PATH.

So try installing packages for all of the above. If it works, running `LD_LIBRARY_PATH=$(pwd) ldd NecroDancer` inside the game's `game` directory should show that all libraries are found.