One of the objectives in the very first mission is to destroy a Heralder. The difficulty here comes from the limited time you have to destroy it when it's moving from island to island. A common strategy is to go ahead to the next docking point when the ship stops and destroy the ships and ground structures first. Then, come back and get the ship on the move again and just lay into it. After it leaves the third base, you only have a short amount of time to destroy it. If you fail, pause and restart.

The first Falchion is on the second stage and is also part of an objective. When it appears, fly away from the island so you're not being fired at by ground lasers. This shouldn't be a difficult fight; try sticking to the flanks and rear and running off to kill other ships if you're bothered.

Simple enough - finish the second stage. Strategy for defeating the Falchion above. You can ignore some of the objectives as well. You'll fail the objective but you'll still advance to the next stage.

This should occur during your first playthrough. Don't bee-line through it and you'll get it within the first few stages.

Sounds simple, but there's a lot going on is this stage and it can become overwhelming. Visit this thread for discussion. In it, Lieu10ant provides this strategy:

Fly northeast to the island that is directly above the red arrows when the level starts and start attacking the island from the LEFT side. There are less enemies that can hurt you. You should be done with this island before you fail the first objective; if you don't, you might want to restart the stage.

On the 2nd island, attack from the SOUTH and SOUTH only. Plant mines near the generator and keep using the vulcan cannon and the regular ol' ground weapon. Use the R3 stick attack to kill enemies that fly around.

For the 3rd island, fly directly SOUTH from the previous island. Now when you get pretty close to it, STAY 2 Kilometers AWAY from the island and fly AROUND IT to the south (from the right side). Now, when you are on the south side of the island, just kill off the generator again.

When you are done with this island, the aggravators (suicide bombers) should be launching. Before you fly to the 4th island, kill those off immediately. Don't waste all the time you've worked for to be killed by these. Now just attack the 4th island from the RIGHT side (you don't have to kill any ground enemies because they wont affect you. Make sure you use your mines.

Now go to the portal and the big ship should be arriving; kill it first and then finish the level off by destroying the 4 'legs' attached to it.

Like the 'Destroyer' trophy, this should be accomplished before finishing the game. Just make sure to hit all turrets, bases, etc. while playing through - it'll make things easier anyway. You cannot start a new game or change difficulties while going for this achievement.

The Searer is the last objective on stage 5. Several strategies are suggested in this thread including dumping your most powerful weapons into it without holding back and destroying the ship one side at a time in order to avoid the weapons on the other.

This occurs when you upgrade all of your weapons to maximum.

There's a lot of discussion going on here and the major strategy that seems to work is to destroy the enemies around the portal when the stage starts so it's easier for the transports to make it through when they get close.

See"Legendary"

See "Legendary"

See "Legendary"

These trophies are all attainable at once if played on hardcore. An overall strategy for the game is to ignore any objective you don't actually have to finish. You'll fail the objective but the game will still progress to the next stage. Each stage will still have objectives that you can't ignore so make sure to follow the strategies above and in the forums for the tough parts.