The Wikipedia Article about this game says that is came out in November 1990. Dunno about that. All I can say is that my girlfriend had it on her DOS computer at her home, when I was in the IDF, and later in Kibbutz Hannaton.
That means we played it over weekends and holidays (though not on Shabbat...). I think she got it for me for my 21st birthday, so late 1991. I'm pretty sure we finished it almost exactly a year later, just the day before Yom Kippur 1992.
So back in the day we were devoted to point and click adventure games, and also it was so much harder to find the answers to the riddles. I do remember that we did have some way to find the answers, especially to the end part, where you have to turn to all sorts of animals. I just can't, for the life of me, remember how we had that, because there was no internet at the time.
It had cost 120 NIS at the time, which is something like 40$ today, not bad for a year of entertainment...