The final scene after the credits, in which the kangaroo says that it doesn't have to have the final word, is the exact copy of the same ending of the original book. Onthe last page of the book there is only one line, saying that the kangaroo doesn't have to have the last word.
The band performing at Jörg Dwigs' party is "Arbeitsgruppe Zukunft" which consists of Marc-Uwe Kling, Boris the Beast, Onkel and Michael Krebs.
At the end of the movie the new homeowner is interviewed who is a penguin. It is a character who moves in at the end of the original book and also appears in the following books "Das Känguru-Manifest" (The Kangaroo Manifest) and "Die Känguru-Offenbarung" (The Kangaroo Revelation). In these books the penguin and the kangaroo are fighting against each other.
The character Jörg Dwigs is a member of the fictional AzD ("Alternative zur Demokratie") party. This is a spoof on the AfD ("Alternative für Deutschland") party, a right-wing populist party. Accordingly, the guests at the Europa Tower presentation include doppelgangers of Marine Le Pen, Geert Wilders and Nigel Farage.
The guy at Dwig's party talking about chemtrails is Volker Zack who also performed the motion capture for the kangaroo.