This section will present useful strategies and information for the completion of the game. This page contains strategies on a broad angle to deal more efficiently with the gameplay elements as a whole. To view specific strategies to defeat Enemies or Bosses, or walkthroughs to destroy the Planetary Bases go to the respective subsections.
Strategy
IPBMs
Each missile will deal 3% damage no matter what type it is, so if a group of 4 missiles hits Corneria they would deal 12% damage. So the priority should be in destroying the groups with the higher numbers, the missile type just makes a difference in the way the missiles are destroyed. Still generally speaking IPBMs are much easier to destroy than Fighters because they travel in a straight course when you engage them, don't fire back, and are generally slower.
Fighters
The damage inflicted by Fighter squadrons is 3% per Fighter (no matter what type they are), but every 2 time units, because of this, and specially in the higher difficulty levels, Fighters pose a higher threat than IPBMs, a couple of squadrons can quickly destroy Corneria if they are not dealt with in time, so do not let fighter squadrons slip behind if you are moving away from Corneria, unless the Satellite Defense System has it's cannon charged (or about to charge) and you think the squadron will be shot down before it can inflict damage.
Viruses
Virus ships are very fast, both in the game map and in Combat Mode. You should try intercepting the group's course with your Arwings instead of chasing it. Once you make contact with the group (while they are still flying towards the Satellite) you will have to be quick in destroying all of them, because they will stand near you for just a moment, and then fly away at a great speed, which even the fastest Arwing models have trouble to keep up with.
The viruses are weak ships, so first use your main weapon to destroy them more quickly. If some of them start to fly away, quickly boost continuously towards them. Then, even though they will still gain distance from you, while you can still see their targeting squares, fire at them with charged shots, which, unlike your main weapon, will still reach them and hopefully take the remaining down before you get a "Enemy out of range!" screen.
If they do get away, as with fighters and missiles, they will move automatically some distance in the map towards their objective (the Satellite in this case), and because of their high speed, even if you chase them, you will probably only have one more chance to intercept and destroy them before they reach the Satellite. Still, chasing them will make you waste some valuable time, so the best option is to be quick in destroying all of them on your first encounter.
Planets
When you start liberating planets, take Meteor first. It's in the center of the map, which is a great location for your Mothership since it will never be too distant. The order of the other planets is not too important, but it may be wise to take out bases near Corneria first, since it will be easier to intercept IPBMs launched from distant bases.
General strategies
On Normal and Hard there's not much strategy involved: just take down missiles and squadrons when you see them, and if there are none, take down a battleship or a base. Give battleships a higher priority on Hard mode because they are equipped with Planet Cannons that can damage Corneria.
On Expert mode, this strategy will not work. If you keep destroying every Fighter or Missile you see on the map before taking on a base or a battleship you will simply get overwhelmed, and if you keep using this strategy to the end, Corneria will fall. Andross will very often send more forces once you get rid of that last IPBM on the map, for instance by ordering battleships to advance to Corneria and fire the Planet Cannon while launching an IPBM from every base.
The key is to be aggressive and take down battleships and bases quickly. Although Corneria may take some damage at first, Andross' capacity to cause future harm will be reduced. In other words, you're taking a short-term risk for a long-term gain. By no means should you ignore enemies that are near Corneria, and if there are several enemies on the map, you should take out those closest to you. However, if there's a lone enemy on right side or even near the middle of the map, you might to well to just take out a battleship (or if there are no battleships, a base). If there's just one enemy and the satellite system is fully charged, you can probably ignore the enemy entirely unless it's extremely close to Corneria. It would take a lot of luck and skill to beat Expert mode without Corneria getting hit, so don't worry too much about it unless the situation truly becomes alarming (but if, for example, you get over 50% damage and most of the enemy bases are still there, you're probably doing something wrong).