Sarien is actually an open source implementation of the Sierra Adventure Game Interpreter
(AGI). Sierra used this interpreter for its early adventure games till 1988. If you ever played
one of these games, you will probably remember it's menu and text parser which was basically
the same for all AGI games. AFAIR there was no mouse support for these games not even
for the menus.
You can find a complete list of AGI games here:
http://www.classicgaming.com/agisci/sierragi.shtml.
1989 Sierra introduced SCI, which featured better resolutions, point and click bars and therefore,
of course, mouse support in the many versions to come. Googling for "Rise of the Dragon" I found
out that it was released 1990, so it was probably SCI version 0 or 01.
There is a nice emu scene, developing homebrew AGI adventures until today, which would be interesting
for the GP32, if it wasn't for the text parser. I never used Sarien on the GP32 though, so I don't know
how this is solved.