Project Spark

Load up a game of Crossroads from the Play menu. Choose any options up until the Character select option. Choose Karlsnor, or keep pressing X until he is available to choose. You can then use the D-Pad to change the difficulty to easy. Once you have protected your town, and need to place the enemy location down, put it as close to your town as possible to speed things up. When you have to fight the guards for the boss, use the D-Pad again to lower the number of enemies. Once you get to pick the boss, keep pressing X until the Goblin King is a choice. Make sure you don't pick the egg goblin choice! Keep attacking the boss until he's dead. You don't have to worry about dying, because you'll just respawn anyway! Defeat him and it will pop; you don't even need to finish the Crossroads level.