Back in the early 2000's, there was a MI-inspired Flash game known as "Search for the golden donkey"
. The creator was planning to release several parts; however, it eventually got cancelled. From what the creator told me, if I remember it correctly, "there's no "Golden Donkey" at all. The words "Search for the Golden Donkey" are the puzzle for the main character, which he must solve in order to save the world"