Metal Assault/Western Forest of Return

Mock Battle
Proceed right. Destroy the wooden targets, kill the enemies, and pickup all the items on the ground as you proceed. At the end, there is a small shack. Press Z to capture it.
 * Zone of Operations: Mock Battlefield
 * Mission Requirements: 0 gold, 0 coins
 * Number of Members: 1
 * Hint: Think of this as a practice field, and it's your mistake.
 * Objectives: Complete mock practice.
 * Mission Rewards: 20 coins, 12 EXP

Battlefield Training
Proceed right, killing enemies and picking up their drops. Get to the flag to complete the mission.
 * Zone of Operations: Entrance to the Forest
 * Mission Requirements: 0 gold, 0 coins
 * Number of Members: 1
 * Hint: Move to the end of the area.
 * Objectives: Go to the end of the area.
 * Mission Rewards: 22 coins, 14 EXP

Jump Tutorial
Proceed right killing enemies and jumping over gaps. Once you reach the plane at the end, press F to board.
 * Zone of Operations: Inner part of the valley
 * Mission Requirements: 0 gold, 0 coins
 * Number of Members: 1
 * Hint: Jumping is key to covering the terrain.
 * Objectives: Board the plane and take off.
 * Mission Rewards: 25 coins, 16 EXP, unlocks

Stomping the Signal
Proceed right killing enemies. You will reach a fence you cannot pass. Take the ladder down, being careful of the enemy waiting at the bottom. Continue right killing more enemies and then climb the ladder. Go left, and watch for the enemies that jump out of the bush. Destroy the communications equipment to complete the mission. You may have picked up a ticket to select a supply box after completing the level. Pick one and you may receive an item.
 * Available Difficulties: Rookie, Veteran
 * Mission Requirements: 0 gold, 0 coins
 * Number of Members: 1 ~ 2
 * Hint: The communications equipment looks like large antennas.
 * Objectives: Destroy the enemy communications equipment
 * Mission Rewards: 27 coins, 16 EXP, unlocks on Rookie; 30 coins, 16 EXP on Veteran

Extraction
Proceed right and watch for the enemies that drop using parachutes. Once you get to the edge of the cliff, wait for the platform to approach. Once it's near, jump on and kill more parachuting enemies. At the other side, get off, kill some more enemies, some of which jump out of a bush behind you. Kill the remaining enemies in the way and those that drop, then board the plane.
 * Available Difficulties: Rookie, Veteran
 * Mission Requirements: 0 gold, 0 coins
 * Number of Members: 1 ~ 2
 * Hint: Beware of the unpredictable landscape.
 * Objectives: Board the transport plane at the end of the area.
 * Mission Rewards: 30 coins, 16 EXP, unlocks on Rookie; 35 coins, 17 EXP on Veteran

Vertical Descent
There's a crate on the left platform that will contain a card. Slowly drop down platform by platform to not suffer fall damage. At the bottom, collect the flag on the left side.
 * Available Difficulties: Rookie
 * Mission Requirements: 0 gold, 0 coins
 * Number of Members: 1 ~ 2
 * Hint: It won't be a cliffhanger if you can find the target flag.
 * Objectives: Reach the bottom of the area.
 * Mission Rewards: 32 coins, 17 EXP, unlocks and

Beauty of the Angle
The nearby technician will brief you on how to use the cannon to the right. Press F to get in. Destroy the targets, the last of which is a tank, to complete the mission.
 * Available Difficulties: Rookie
 * Mission Requirements: 0 gold, 0 coins
 * Number of Members: 1
 * Hint: The key is controlling the angle AND power of the cannon.
 * Objectives: Destroy all targets in the area.
 * Mission Rewards: 35 coins, 17 EXP

Secure the Vehicle
Take the upper path and destroy the crates you see. One of them should have a supply card. Kill all the enemies you encounter and proceed right. Lots of enemies will come at you, including some parachuting in. Once you reach the vehicle, press Z to occupy it.
 * Available Difficulties: Rookie, Veteran, Elite
 * Mission Requirements: 0 gold, 0 coins
 * Number of Members: 1 ~ 3
 * Hint: Use your Occupation skill on the vehicle.
 * Objectives: Secure the vehicle at the end of the area.
 * Mission Rewards: 40 coins, 17 EXP, unlocks on Rookie, 45 coins, 20 EXP on Veteran, 50 coins, 22 EXP on Elite

HMK-29 Launch
Go right and get into the tank by pressing F. Drive the tank to the right side. You can use any of the weapons to kill the enemies, or just drive over them. Be careful of the enemy with the Rocket Launcher as that can do a significant amount of damage to the tank. If playing alone, it's sometimes easier to get out and kill the enemies with regular weapons. Otherwise, the second player can man one of the other guns on the tank. On Elite, there is also a mini tank at the end.
 * Available Difficulties: Rookie, Veteran, Elite
 * Mission Requirements: 0 gold, 0 coins
 * Number of Members: 1 ~ 3
 * Hint: Mission fails if tank is destroyed.
 * Objectives: Take the tank to the end of the area.
 * Mission Rewards: 42 coins, 20 EXP, unlocks on Rookie, 47 coins, 22 EXP on Veteran, 50 coins, 24 EXP on Elite

Enemy Attack
Proceed right and kill the few enemies. After you pass the tree, two stronger enemies will come out and attack you from behind. Continue onto the bridge where enemies will be waiting, and more will drop from the sky. Once you reach the edge, a few more enemies will parachute in along with a small flying helicopter enemy, two on elite. Destroy that, kill some more enemies, and prepare yourself for a boss fight.
 * Available Difficulties: Rookie, Veteran, Elite
 * Mission Requirements: 0 gold, 0 coins on Rookie, 1 gold, 0 coins on Veteran, 0 gold, 0 coins on Elite
 * Number of Members: 1 ~ 4
 * Hint: Eliminate all enemies in the area.
 * Objectives: Eliminate all enemies in the area.
 * Mission Rewards: 42 coins, 20 EXP, unlocks and Attack by Force on Rookie, 45 coins, 22 EXP on Veteran, 47 coins, 25 EXP on Elite

The boss is a tank. Various enemies will parachute in or run at you. The tank itself will fire powerful bullets, or shoot a giant ball that does a lot of damage. Keep killing the enemies and shoot the tank until it is destroyed to complete the mission. On higher difficulty levels, you must clear the tank's HP bar multiple times to defeat it. The last layer is always red.

Rush

 * Available Difficulties: Rookie, Veteran, Elite, Master
 * Mission Requirements: 0 gold, 0 coins
 * Number of Members: 1 ~ 2
 * Hint: Break through to the core area.
 * Objectives: Eliminate all enemies.
 * Mission Rewards: 67 coins, 17 EXP on Rookie, 70 coins, 20 EXP on Veteran, 72 coins, 22 EXP, unlocks Master on Elite, 75 coins, 25 EXP, unlocks Legend on Master, 77 coins, 27 EXP on Legend