In Albert's flat there's a picture of him with Sir Terry Pratchett
Director Massimo Fenati also wrote the script and voiced the Snow Baby character.
There's a poster on the wall of Tiffany Aching in concert. Tiffany is a witch in Terry's Discworld books
Granny has a gnome on the windowsill outside her house, possibly a reference to the Gnomes in the Bromeliad Trilogy (Truckers, Diggers, Wings)
The red & white rocket on Albert's bedroom shelf is the same model Tin Tin used in Explorers On The Moon.