Instructions
Go to the Machine Labyrinth and defeat the boss "Ghost Pendulum." Beat this boss by jumping on the blue, yellow and red balls rotating around him to cause the balls to hit his head. Avoid his attacks and continue jumping on the balls until he is defeated. You will be rewarded with Sol Emerald 1.
Find and complete the Hidden Island 6 level which is found two squares down and one to the left of Southern Island to receive Sol Emerald 2.
Defeat the Coral Cave boss, "Ghost Kraken," to gain Sol Emerald 3. To defeat it, avoid its attack by running or jumping out of the way and jumping on its crystal arm to attack it. After seven to eight hits, he should defeated.
Locate and complete the Hidden Island 12 level, found up one square up and three to the left of Pirates' Island on the map. Completing this course will reward you with Sol Emerald 4.
Complete the Hidden Island 8 level which is located three squares down from Kylok's Island on the map to receive Sol Emerald 5.
Defeat Captain Whisker and Johnny, the Pirates' Island bosses, to receive Sol Emerald 6. Jump on the two bosses to attack them, as they do not have any special weak spots you must attack. Avoid them when they jump up and do the "Shockwave" attack, and also when Whisker grabs Johnny and throws him at you. They are invincible during these attacks.
Beat "Ghost Titan," who is fought immediately after beating Whisker and Johnny, to receive Sol Emerald 7, the final Sol Emerald. Ghost Titan is located in the Big Swell and is one of the most difficult bosses in the game. Kick the rockets it shoots back into its shield to destroy them. Stay next to one of the turrets during his other attacks to avoid them. Once the shield is destroyed, jump on the cannon several times to destroy it. Jump into the turret and press "A" to fire Sonic at the Ghost Titan's head several times to defeat it.