When starting a new game, instead of selecting "Start", enter the "Password" screen and press Start. You will get four lives to begin with instead of the normal three.
When facing Dooku in last level, quickly press Right + B, B for a slashing combo. Additionally, when facing Dooku in last level, quickly and repeatedly press Right + A, A for another combo. For a 3-hit combo, hold A and press Foward, Forward, Back very quickly (while facing right). This is also very effective against multiple enemies or against Dooku.
When facing Dooku on the last level, do not bother using The Force. Before you can use it, he will use it and do the damage. You will not inflict damage at all. Additionally, press L + Right until he is on the ground. Then, immediately press the L + Down. Repeat this until he is defeated.
You will face Jango Fett for the second and last time in level 9. Do not bother using the Force. Keep slaying enemies to collect enough Force Boosters to fill up the Force Meter. Once full, enemies will drop hearts. Press A + Up to thrash your light-saber over your head. Hit Jango with this and he will fall to the ground and jump back up in the sky. Before he can do so, jump and press A to kick. Keep jumping at him and kicking until you reach the point where you cannot move forward. If you can, before you get to the end, press A, Forward(2). This will make Mace Windu do a neck chop sort of maneuver and give Jango Fett lots of damage. After killing him, defeat all remaining droids on the screen to complete the level.
-Some codes from: firstname.lastname@example.org and Gkenlon2@cs.com