Asteroid Sweep is the first real Gummi Mission in Kingdom Hearts II. As such, it is the perfect level to get used to the Gummi Ship's controls.
This level is excellent to use the Full Auto ability to rapidly fire at nearby enemies and asteroids to rack up points. Otherwise, keep a finger constantly on the attack button to cut through enemies. There are numerous asteroids littered across the level and only require a few hits to destroy one. Watch out for the Bomb Bell enemies, as they will attempt to damage you kamikaze style. Should a Bomb Bell get close to you, safely get away using a Dodge Roll before it blows up. To defeat the Shield enemies, you must use a tactic similar to the one used against Fat Bandits and Large Bodies; wait until you can shoot them from behind. The goal in this mission is to obtain enough medals in order to earn the numerous completion bonuses and treasures. Quickly clear out all the enemies and watch for more to come. Certain enemies that hold a lot of medals, such as a gold color Knight Head, only spawn after the enemies that appear before them are defeated first.
Any Gummi Ship with lots of projectile, and lock-on gummis will get you through the level with a fairly good amount of medals. However, the addition of teeny ships are invaluable for those wanting an S rank. Also, applying optional abilities such as the cannon upgrade and laser upgrades work well, too.
Mission two is all about destroying a certain number of ships. The number of ships you destroy determines which treasures you will get. Similar to the strategy used in mission one, watch out for dive bombing enemies, literally, and blast your way through the hordes of enemies. In this mission you must keep your finger constantly on the attack button. Immediately after you start the level you are hit with the first wave of enemies. Blast through them and continue on. Throughout the level you'll run across stronger enemies that will attempt to dissuade you from attacking the smaller, easier targets. Carefully position yourself to take out the smaller enemies, but still be hitting the stronger enemies. A red Spider will appear twice in this level- thankfully by itself, allowing you to focus solely on it. Avoid its laser barrage by dodge rolling. To defeat this Spider, you must use a tactic similar to the Guard Armor; take out its extra appendages first, then strike the main torso.
To get 100 percent completion on this mission, you might have to make a return visit with a stronger Gummi Ship. Some of the higher level original Gummi Ships, such as the Falcon/Highwind Peak work well here.
As the higher mission number would suggest, this mission is harder than the previous two missions on this level. This mission requires you to rotate the camera yourself. You're not truly alone, though, as you will receive a red alert beep hinting where you should position the camera. Your radar and laser/lock-on gummis are your best friend in this mission. Never take your finger off of the attack button, it may just cost you the mission. There are plenty of enemy ships to be destroyed in order to rack up the points necessary for high scores. Another red Spider appears twice in this level, only this time it is not alone. The Spider will either: show up by itself then be followed by a massive group of enemies, or spawn in the middle of a group of enemies. This makes destroying both the Spider and other enemies very difficult. Instead of focusing your strength on the Spider, shift the camera around when needed and blast the smaller enemies. When both the Spider and massive waves of enemies are flooding you, keep shooting them down, but also dodge roll their attacks. It is during these moments that you can potentially fail the mission. If you can, take out the Spider to receive a hefty amount of points. If your ship gets surrounded, unleash Full Auto and rotate constantly. This increases your chances of eliminating key enemies that trigger the red and gold enemy ships.
This is a hard mission, even for stronger level ships. In order to get the higher rankings, you must use a higher leveled, weaponed Gummi Ship. The use of Teeny Ships, while optional, could mean the difference of earning a rank.