In Drek's Fleet, there is a 6th ship that is used for the Drek cutscenes in game. The area is accessible using a cheat device, however it has no collision and will instantly kill Ratchet if he touches the ground.
In the HD version of the game on the PS3, there is a trophy named "These are not the droids you're looking for..." This references a line from Star Wars Episode IV: A New Hope.
Helga's original concept design can be seen in the winter 2003 Jampack demo, where she dons pure Black with double stripes on her shoulders instead of her Robotic arms and qwark symbol on her black jumpsuit.
The name of one of the skill points, "Going Commando", was later used as a subtitle for a later game in the series, Ratchet & Clank: Going Commando.
On planet Pokitaru, there are starfish scattered around the beach and all of them show the image of former Insomniac Games employee Dan Johnson. Johnson often appeared as an easter egg in ##Insomniac Games## titles.
In the Blarg Tactical Research Station there are green computer monitors scattered throughout the level. Former Insomniac Games employee Dan Johnson appears on one of the monitors at the edge of the landing area of the BTS Station.
On the cover of the US release are a number of weapons in the background. One near Ratchet's head reads "____NTO-RAY". No weapon in the final game fits this name, nor looks like the image associated with it. However, one of the cut weapons for the game was called the "Giganto Ray", and it is likely that this design was left on the cover by mistake.
In Spyro 2: Ripto's Rage! there is a large orange enemy with a wrench and a small robot accompanying him. They seem to have served as the basis for the characters Ratchet and Clank. Insomniac Games developed both titles.
There is a hoverboard competition hosted by a curvy alien, who is set to enter into the race. If you choose to ditch the hoverboards and spend your time executing side-flips and back-flips instead, you'll find that for each mid-air stunt, her breasts will begin to enormously inflate.