After installing "runescape" (by "sudo apt install runescape") I could start
the program "runescape", but it stopped executing at 98%.

I could adjust the file "/usr/games/runescape" so that error messages were
shown, which revealed a "java.lang.NoClassDefFoundError:
java/util/jar/Pack200".

The currently installed Java-Runtime is openjdk-17-jre. It appears that the
Java-class Pack200 is deprecated since openjdk-11 (see:
https://openjdk.org/jeps/336 ) and removed since openjdk-14 (see:
https://openjdk.org/jeps/367 ).

Therefore the package "runescape" won't work any longer. I don't see a way to
fix this bug (other than adding old and deprecated java-classes). What do you
think?