To defeat the Zillo Beast, get about 100,000 credits and go to every build area and build a turret on each one. Check all the build areas and find the one that lets you build tanks. Build plenty of X-130 Tanks and you're done. All you have to do now is watch, or maybe help a little.

Unlock the following Minikit characters for purchase in the store by performing the corresponding tasks:

CHARACTER - HOW TO UNLOCK
Admiral Ackbar - Collect all 10 Minikit pieces on Gungun General
Boba Fett - Collect all 10 Minikit pieces on Grievous Intrigue
Captain Antilles - Collect all 10 Minikit pieces on Innocents of Ryloth
Chewbacca - Collect all 10 Minikit pieces on The Zillo Beast
Clone Shadow Trooper - Collect all 10 Minikit pieces on Blue Shadow Virus
Darth Maul - Collect all 10 Minikit pieces on Rookies
Darth Sidious - Collect all 10 Minikit pieces on Geonosian Arena
Darth Vader - Collect all 10 Minikit pieces on Legacy of Terror
Darth Vader (Battle Damaged) - Collect all 10 Minikit pieces on Ambush!
Greedo - Collect all 10 Minikit pieces on The Hidden Enemy
Han Solo - Collect all 10 Minikit pieces on Duel of the Droids
Imperial Guard - Collect all 10 Minikit pieces on Castle of Doom
Lando Calrissian - Collect all 10 Minikit pieces on Shadow of Malevolence
Luke Skywalker - Collect all 10 Minikit pieces on Weapons Factory
Obi-Wan Kenobi (Episode IV) - Collect all 10 Minikit pieces on Jedi Crash
Princess Leia - Collect all 10 Minikit pieces on Battle of Geonosis
Qui-Gon Jinn - Collect all 10 Minikit pieces on Storm over Ryloth
Rebel Commando - Collect all 10 Minikit pieces on Lair of Grievous
Stormtrooper - Collect all 10 Minikit pieces on Liberty on Ryloth
Tusken Raider - Collect all 10 Minikit pieces on Hostage Crisis
Vader's Apprentice - Collect all 10 Minikit pieces on Defenders of Peace
Wedge Antilles - Collect all 10 Minikit pieces on Destroy Malevolence

Use the force to pick a Super Battle Droid up and make it fire rapidly. Use this to destroy gold lego structures.

Score modifiers are the best. Aim to get the red bricks that unlock each one, and also have all of the ones you've unlocked on at once. The purple stud which appears next to the shop normally gives you  about 150,00 or so, so with modifiers:

2 x 15,000=30,000
2 x 4 x 15,000=120,000
2 x 4 x 6 x 15,000=720,000
2 x 4 x 6 x 8 x 15,000=5,760,000
2 x 4 x 6 x 8 x 10 x 15,000=57,600,000

Now that's a lot of studs! Unlocking all the characters/hints only costs around 4,000,000 total, so you're good to go.