I sadly don't have a Debian/Ubuntu machine. I'm living in the luxury called Guix System, which basically means none of my packages will ever lack a dependency in their closure.
That being said, you only said "it did build", not that you installed it. Can you check the contents of /usr/local/share/guile, as well as your $GUILE_LOAD_PATH in the shell you're trying to configure this game in? If that all looks fine, have a peek at the output of the Guile REPL when you enter
scheme@(guile-user)> ,use (tsukundere)
Note that the scheme@(guile-user) here is Guile REPL prompt.
I'll try compiling all the debugging steps here into a more useful README next time.