Apparently in the old gtk version, there was an activity to train using Left and Right clicks.
( -> Actually after double-checking, I didn't find such activity in the old gtk version, at least not in the last 15.10.
Maybe it was an unofficial activity made by a user? Anyway, it looks like a potentially good activity to add.)
The described activity was part of Pysycache : http://pysycache.org/contrib/UserManual/UserManual-en.pdf
(the french pdf actually has more info about it: http://pysycache.org/contrib/UserManual/UserManual-fr.pdf )

We just had a request from a user who was missing this activity.
As this kind of activity is not relevant for phone/tablets/touchscreen-only devices, it should be enabled only on computers (devices with a mouse/touchpad).

Description: There are pinguins and (another animal, to check...), and their respective home. Users need to drag pinguins with the left click to their home, and drag (the other animal) with a right click to their home.