When trading with any empire, the theme song from the 1983 game M.U.L.E., an influential multiplayer game published in North America by EA, can sometimes be heard in the background. A song also called "M.U.L.E." can be found in the song library for use in adventures.
Contributed by MehDeletingLater
When the player's creature evolves into the tribe stage, a cutscene will play in which the creature learns how to use a stick as a weapon, then, as a way of celebration, throws the stick into the air and it lands on the creature's head.

This cinematic sequence is a parody of the opening sequence from the Stanley Kubrick film 2001: A Space Odyssey, where an ape learns how to use a bone as a weapon. Additionally, the intro cutscene from Spore features a remix of 'Sunrise', which is the initial fanfare of the tone poem "Also Sprach Zarathustra".
Contributed by ZpaceJ0ck0
The Monolith tool that's used to raise a creature to the next technological level is a nod to the monolith from the film "2001 A Space Odyssey". In the film, mankind's early ancestors were given intelligence from a mysterious black monolith from space.
Contributed by GhostLight