The first thing you will have to do when you start a new game is to choose a difficulty level. The difficulty levels will affect the gameplay experience drastically. On each difficulty mode the levels will be different, events will change, you will fight new types of enemies, and the forces you encounter will be more numerous and harder to defeat. This makes each difficulty level a part of the game on it's own.
However, the names of the difficulty levels could be misleading. Judging by the content each has, Normal could be considered more as a training or easy mode, having some of the main game's features cut off, and being the only mode with initial game instructions to guide you. Hard could be considered the standard difficulty level, with all main game features present; and Expert could be considered as a challenge mode.
This is the list of all main differences:
All battleship and planetary base levels will be different, generally being harder versions the higher the difficulty is, containing more complex puzzles to open doors and more numerous enemies. Also every difficulty level has its own Pepper Coins to collect, and some levels will have land bosses which do not appear on other versions of that level.
Battleship cores and base generators will be harder to destroy, having more targets to hit and/or more defenses.
Star Wolf fighters will be smarter fighting, reflecting more of your shots with barrel rolls and shooting more charged shots.
Andross will have one more battle phases for each difficulty level.
Pick targets deliberately on the map. Move the cursor over enemies to see how many there are, sometimes you can ignore single missiles and small squadrons of enemies. However, beware of large bombs and large enemy ships.
If one character is badly damaged, press SELECT to switch to the less damaged one. Try to get back to your mothership to repair. If you have Peppy or Slippy on your team, you won't have to visit the mothership as often because they can take more damage.
Use the Mothership to warp to targets of opportunity, especially right at the beginning. If a battleship is right next to an unoccupied planet, you can warp right next to it and destroy it quickly, preventing it from launching more ships.
In combat, you will turn much faster if you Brake and press L or R.
Fights with Star Wolf take a long time, which means Corneria can take a lot of damage. Don't be afraid to run away if you have an escape route on the map. You may want to warp the Mothership to avoid them.
If you fight an enemy when Star Wolf is nearby, they may interrupt you. You can use this to your advantage, taking out two enemies at once.
When fighting Star Wolf, use Miyu's or Fay's charged shots. Their rapid charge lets them land more hits. If you have very good timing, you can land charged shots with slower characters.
When you start a fight with a battlecruiser, boost all the way to the entrance. You can ignore the enemies outside of the ship.
Don't use Peppy or Slippy to take out bases. Their slow speed means that Corneria takes more damage while you try to complete a mission.
Alternate between destroying planet bases and destroying motherships. This will slow down Andross's reinforcements.
Use bombs to clear rooms and defeat bosses quickly. The faster you can finish a mission, the less damage Corneria will take.
The best place to find Blaster upgrades (and other items) is on planets. Switch characters to make sure the character you want gets it. Boost around the zone quickly and home in on green squares.
Levels and enemy groups are persistent. If you take out half of a squadron, it will do a lot less damage when it makes it to Corneria. You can delay a missile launch if you land on the planet, destroy the missile on the map, and run away (though you may want to consider grabbing a few items before you leave.)
Boss health is NOT persistent. If you fight a Star Wolf member down to half health and then run away, he'll be at full health the next time you fight him. Decide before you start a fight whether you should finish it.
Don't get discouraged! It can be overwhelming at times, but keep with it and have fun!
