The standard German retail box of the game includes a Steam version of the game. You need a Steam account to install this version of Chains os Satinav. A DRM-free version without required internet connection can be found in the "Die Abenteuer" box, which includes both Chains of Satinav and the sequel Memoria. Also, there is a DRM-free download version of the game next to the Steam key, whenever Chains of Satinav is in a Humble Bundle sale or store.
This is an issue with the mouse over text, which is already fixed in the Switch version of the game. These spots are empty on purpose, since each page has nine spots, while the game contains 13 longer videos, 12 shorter videos (which are not listed in the Extras section, since they are only between 5 and 20 seconds long) and the credits.