One of a series of Kosmos games based on the My Secret Unicorn books by Linda Chapman.

In Germany, the series goes by the name, "Sternenschweif" (Star Tail) and the books are also published by Kosmos.

Geheimnisvolle Verwandlung is based on the book by the same name (the first in the series) and the game is correspondingly themed. The game is played with 48 covered tiles and the objective is to reveal them one by one in hopes of locating six items that will enable the titular pony to transform into a unicorn. There's a push-your-luck element to it and if one uncovers a tile showing Buddy, the dog, or a repeated item, you lose everything you've uncovered that turn.