Mode: Battle Enemies
Enemies: Battle Droid, Grievous' Bodyguard
You won't have to move much here. Just move across a couple bridges, enabling enemies to come in very fast from all directions. You will seldom see a Grevious' Bodyguard here.
Mode: Collect Studs
Enemies pile up into crowds very fast. Be careful, and make sure to look for power-ups. This should go by quickly if you find a container dense area with at least one power-up.
Mode: Stud Hunt
Hunt: 394,000 studs
This goes by quickly if you spawn around the upper left area.