Air Tortoise

Air Tortoise or sometimes Sky Turtle is the name given to a near-ubiquitous series of Missile Launchers that have appeared in every major EDF game except Earth Defense Force: Iron Rain.

Description
Given that they appear in multiple games in different continuities there are few things that can be said that are true of every variant, but all appearances share some gross similarities. All variants share the same general quality of being a single-shot launcher that fires a powerful but comically slow guided missile with broad splash damage. Their low speed means they are ineffective against fast-moving enemies, which can sometimes outrun them until the missile disappears, and dangerous to use against enemies that close range quickly due to their wide area of effect.

Global Defence Force
The Leviathan is among the "super rare" weapons of Global Defence Force, and would later influence a whole other class of weapons called Leviathan for the Fencer class starting in EDF 2025. In the original PS2 version it has an interesting and very odd bug associated with it where it would sometimes not only fail to destroy scenery, but actually reinforce it, resulting in minor scenery objects like trees, bushes and buildings ending up with about 24,000 health. This can be extremely effective against certain enemy types as it turns these objects into extremely tough barriers. The glitch was fixed in the PSP version and is not present in Invaders from Planet Space either.

Variants
2017 does not give range figures for homing weapons.

Insect Armageddon
The Air Tortoise is a one-off Tier 4 weapon for the Battle Armor that is only available as an in-mission collectable. Its power is completely disproportionate for its tier, but it is extremely slow and takes a long time to reload. One way to make very effective use of it is fire it into the ground and raise the Battle Armor's shield: since damage cannot overrun the shield, this will clear out enemies around the Battle Armor in a similar manner to the Blast Wave ability.

The Air Tortoise has no "sweet spot" in its active reload bar, so any attempt to active reload it will result in a failure that makes the reload even longer.

2025 / 4.1
With the implementation of 2025's new lock-on mechanics the Air Tortoise lost its most lethal feature of locking on to enemies directly behind the player character and graduated to "interesting oddity" in the process. Air Tortoises no longer use the generic 2017 twin-tube launcher model (which became the Emerald) in this game, instead having their own models. All types are shown as a rail launcher with a retro-futuristic missile mounted on top of it.

As with other portable lock-on weapons, the fire button does not immediately launch the missile. Instead, holding it will bring up a red bounding box in the middle of the screen: this is the lock-on area. If the box is placed over an enemy (or a point designated with a Guide Beacon or Laser Guide Kit) that is within the weapon's lock-on range, a cursor will appear over it and a beeping lock-on tone will sound: holding it within the bounding box for the lock-on time will result in the cursor changing, along with a louder single beep indicating a lock. At this point, releasing fire will fire the weapon. If the player wishes to abort the launch after locking on to a target, switching weapons will cancel firing.

The Air Tortoise now uses a lofted trajectory, lobbing the missile off the launch rail in a ballistic arc before the main engine ignites a short distance away, followed by a climb-out phase and then the missile (slowly) chasing the target, aiming to fly as straight a course towards it as possible. If the missile hits the ground during the initial launch phase it will explode, so it is a very bad idea to fire the Air Tortoise aiming down or on uneven ground. Like all lock-on weapons, the Air Tortoise will "remember" a lock for a short time even if the target moves outside of the bounding box: this can be used to aim the launcher up to avoid the missile striking the ground or any nearby objects.

Of the three variants available, the middle one is the most balanced: the initial variant is afflicted by a long lock-on time, while the final variant has such a cripplingly slow reload that the Air Tortoise 02 actually has slightly higher practical DPS.

In spite of their flight speed being slow enough to outrun them on foot, they are stopped by Shield Bearer screens in the same way as any other projectile weapon. Because they are so slow, it is possible to roll ahead of a missile in flight and launch another: by doing this repeatedly, a Ranger can stack up an enormous amount of damage in mid-air that will all be delivered to an enemy before it can react to the initial impact.

Variants
"Flight time" is a measure of how long the projectile exists for after it is fired; it is deleted if it has not hit anything before this. Figures in (brackets) are EDF 4.1 changes.

EDF 5
The Air Tortoises function very similarly to how they did in the previous game, with the main bonus being from the upgrade system: this gives them superior range and damage to their previous incarnations when fully upgraded, and means all variants can be upgraded to a very fast lock-on. However, their reload times only upgrade to the same they were in the previous game when maxed out, meaning the second variant still has better DPS than the third.

Variants
All stats reflect the maximum level for the respective weapon. Flight time figures have not yet been calculated, but can be presumed to be roughly the same as before.

Trivia

 * Lofted trajectory is a launch mode used by some real weapons such as the FGM-148 Javelin. In real examples, the missile's warhead is armed by inertial forces from the flight motor firing, preventing an explosion if it hits the ground during the initial soft-launch phase.