Could not get this running on Debian testing. Here is my solution. Would not start saying it couldn't find /usr/lib/dri/iris_dri.so. I found it in /usr/lib/x86_64-linux-gnu/dri/ and linked /usr/lib/dri/ there. Now I get a bit further, but get this error.
INFO: started Skeletris version: 1.0.3-BETA
INFO: development mode: False
INFO: pygame version: 1.9.3
INFO: initializing sounds...
libGL error: MESA-LOADER: failed to open iris: /tmp/_MEIyt5EOV/./libstdc++.so.6: version `CXXABI_1.3.8' not found (required by /usr/lib/dri/iris_dri.so) (search paths /usr/lib/x86_64-linux-gnu/dri:\$${ORIGIN}/dri:/usr/lib/dri)
libGL error: failed to load driver: iris
libGL error: MESA-LOADER: failed to open swrast: /tmp/_MEIyt5EOV/./libstdc++.so.6: version `CXXABI_1.3.8' not found (required by /usr/lib/dri/swrast_dri.so) (search paths /usr/lib/x86_64-linux-gnu/dri:\$${ORIGIN}/dri:/usr/lib/dri)
libGL error: failed to load driver: swrast
X Error of failed request: GLXBadContext
Major opcode of failed request: 150 (GLX)
Minor opcode of failed request: 6 (X_GLXIsDirect)
Serial number of failed request: 35
Current serial number in output stream: 34
So I found libstdc++.so.6 in /usr/lib/x86_64-linux-gnu/libstdc++.so.6. Rather that creating another symlink, I started the game with LD_PRELOAD=/usr/lib/x86_64-linux-gnu/libstdc++.so.6 ./Skeletris and it worked. Seems like Debian puts things in /usr/lib/x86_64-linux-gnu/ that are expected to be in /usr/lib/ and I'm not sure why. I blame Debian. Looking forward to playing this game though.