There are quite a lot of American games on the market and a few Hungarian ones, but this is the first German game I've seen. It's a graphic adventure, translated into English except the names of the rooms, which are still German. This doesn't detract from the playability of the game, it just looks odd.
The instructions sheet was presumably not the final version, as it was rather crudely duplicated and referred to the characters as Kunibert and Kunigunde rather than Tristan and Isolde. The on-screen instructions were more helpful.
Commands are entered by single-key selections from a menu displayed at the side of the screen, which is very unusual. You have to guide Tristan around a castle in search of Isolde, who will then follow him back to the start. There are a few items to pick up along the way, and some monsters to avoid. of course.
As adventures go, this one is easy. Success seems to require luck rather than skill, there being very few puzzles to solve on the way.