No, and what "levels" do you refer?
You choose the next planet that you want to visit and before the final world, you can revisit all the planets you want
Furthermore there's very little to do besides the campaign, and the "worlds" are rather small.
Personally I think it'd be cool to parade around the galaxy at will after you win the game, with nonplayables spouting the appropriate dialouge ofcourse (lightside="Thank you for saving us", darkside="please, I beg you, show mercy")
If you want to change your Pc's level i suggest the add exp cheat!
"addexp 99999" or "addexp 1000" or "addexp X"
But to warp you can use the warp cheat
"warp 003ebo" "warp 501ond" OR You can use Lit Ridl's Warp Armband V1.2 (The origonal was by Sithrevan)
Yup that will work as well as there are several different modules within the planet :D