Collectibles in the game; Nuclear Fuel Rods, Gourds, License Plates and Alien Ship Parts. Skillpoints are also classed as a unique type of collectible.
“Skillpoints (or skill points) are a unique type of collectible in The Sims 2 that contribute...Skillpoints
“Alien Ship Parts are one of the four collectibles in The Sims 2. Unlike the other three...Alien Ship Parts