[2][3] The player controls Hans Kloss, the fictional protagonist of the Polish TV series Stawka większa niż życie, during World War II.

[3] The player's task is to find 21 pieces of the plans of a secret Nazi weapon (the V-1 flying bomb), hidden within safes found around the corridors of the Wolf's Lair bunker, as well as a seal located in one of the rooms.

[7] Hans Kloss was programmed by Dariusz Żołna, who had already developed a number of simple games published in the Tajemnice Atari magazine, but had ambitions to create "something bigger and more interesting".

Three other developers worked on the game: Sebastian Michna (artist, who created the protagonist's animation and the title screen), Daniel Kleczyński (music composer) and Bartek Gałązka (level designer).

Dariusz Żołna created some of the art assets: the background graphics, the Goliath mine sprites, the font and the plans of the V-1 flying bomb, which were copied by hand from a book illustration.

The reviewer in Tajemnice Atari described it as "highly interesting and addictive" and praised the variety of the gameplay, as well as high-quality graphics and music; she also commented positively on the light-hearted aspects of the game, such as Kloss vomiting after eating too much food.