SAS: Zombie Assault 4

Zombie Assault 4 began open beta on May 11th, as announced on the forums by an administrator. On a blog published on May 14th, it was announced that a mobile port of SAS 4 was "a long way into development."

Pre-release
Zombie Assault 4 was said to be in early development on a Ninja Kiwi blog on January 22nd, 2014. On a blog published on February 28th, an image of the title screen was put on Imgur, and put on the blog as a 'hidden' link in the response to the question "Is it possible tf gameplay - a soldier shooting zombies inside a building while a timer above counts down. It was seen here that turrets, premium ammo, Grenades and Cryo Grenades would be included.

Plot
Aboard the Kurios Space Control Station in Aartis System, an unknown virus has infected most, if not all, humans. At Bay 10, Military Space Shuttle Mantis 12 is unable to leave due to malfunctioning ramps. As a result a team of SAS forces begins to defend the rear of the shuttle. Eventually, the SAS manages to takeoff, but not before being attack by a mutated boss zombie, which, in-game, changes depending on your character level. When the SAS finishes clearing the shuttle, it departs.

Meanwhile, upon hearing of the news about the virus, dubbed the Thera Virus, the president begins to address worried citizens that all will be taken care of. While on TV, an intelligence officer orders the same SAS team from the Aartis system to recover a vaccine on Thera discovered by Combot, an AI designed for emergency defense, in order to stop an outbreak on Aartis, the known planet where the human race resides. Since the president's address to the people, he has also approved of signaling the Jolt Ship in Thera's orbit to fire its WMD to destroy the entire planet, since there were no signs of life at the time. The team has only less 15 minutes to retrieve the vaccine and get out alive before they are destroyed along with Thera. The team of SAS fights their way through a subway station to reach a train, which leads to a lab containing the Vaccine. Once they retrieve the Vaccine, the team manages to shoot their way through a crowded street filled with all sorts of zombies, including another mutated boss zombie(s).

After retrieving the vaccine, the SAS Team boards a dropship and departs. A few moments after the SAS Team departs, the Jolt Ship destroyed the planet, killing all the zombies on it. ComBot then orders the team back to Aartis System since the virus has reached a heavily populated city of Aartis. There, citizens have barricaded themselves in, but won't last long with the hordes of zombies abound. The SAS are then ordered by ComBot to rescue as many survivors as possible and neutralize any zombies in the area, including survivors who become infected. After rescuing any survivors in the area, the SAS are attacked by another boss zombie.

Upon rescuing civilians, the SAS team are soon briefed about Combot suddenly becoming compromised as the Virus has become a digital pathogen. The SAS arrives at a market area as there are pods that seems to be harvesting humans and mechanical parts, all of which contain either zombies or drops. While fighting through the area, the SAS discovers a Purge nest spawning zombies. When they reach the other parking lot, the SAS discover a Minion Egg. Four minion eggs surround a much larger boss egg, and each minion egg releases a large group of powerful zombies when destroyed. When the SAS Team approach the Boss Egg, spikes emerge from the ground beneath their feet in an attempt to impale the SAS Team. After destroying the Boss Egg, a Boss Zombie emerged, which was dispatched by the SAS team.

Soon, the SAS are guided to a mansion overrun by zombies with a VIP inside. After searching various hiding spots in the mansion, they finally locate the VIP. He is quite whiny as he will call out the SAS team for picking up a droppable item he claims belongs to himself. Eventually reaching the landing zone, the SAS and the VIP notice that Zombdroid Servants and Zombdroid Soldiers are attacking the group. If the SAS manages to hold off the Zombdroids, the VIP will say in relief to get out of there. If the SAS manages to hold off the attack, but the VIP's health is half-way down, the VIP will complain how he was "half-dead".

The SAS are then sent on a mission to a hospital without power. The only way to restore its power was through switches throughout underground tunnels. The SAS went through the zombie-infested tunnels and turned on the power, but Combot activated four Automatic turrets and, later, one or more Loaderbots. The SAS must battle these enemies to complete their mission.

Finally, the SAS are sent to a city that was partially barricaded. Remaining survivors of Aartis are awaiting extraction, but zombies are swarming too quickly to set up barricades. The SAS must defend the city from zombies swarming in from the places without barricades. The mission consists of eight waves, each one increasing in difficulty. The SAS cannot let more than 25 zombies through the lines of defense. There is a final boss at the end.

Gameplay
There are three character classes, each with their own unique skills, 94(+2 upcoming) weapons with 11 unique augmentations, and 74 body armor pieces with 13 different augmentations. All of the armor pieces and weapons are obtained by strongboxes, which are obtained in several ways. There are total of 12 industries that make weapons and armors. Like with Zombie Assault 3, 4-player co-op multiplayer is included. Chat is included in multiplayer. Also, the players can now play multiplayer without having a full-room. Passive upgrades on weapons, grenades, turrets, and many more (called Masteries ) were also introduced to the game by the 8th October patch.

The style of gameplay in Zombie Assault 4 differs from 3: rather than the player defending themselves from waves of zombies on a map, the player progress through maps in level-like fashion with objectives to complete. Additionally, each level has an 'intro', providing backstory for each level.

Missions

 * Onslaught
 * Vaccine
 * Survivors
 * Zombie Pods
 * VIP
 * Power Out
 * Last Stand

Character
In SAS: Zombie Assault 4, you are allowed to have two different character slots open, until one of them reaches level 20, unlocking a third slot. Another slot is unlocked when a character reaches level 60. You also have the option to purchase a fifth and sixth slot for 20 NK Coins.

When creating a character, you can choose between Assault, Medic, and Heavy, from left to right. The description for each is as followed: "Assault troops are used by the Federation when speed, surprise, and violence of action are required above all else". "In addition to their deadly SAS training, a Medic employs a number of fast and efficient means of human tissue repair". "Heavy Gunners' special skill make them ideal for delivering overwhelming force to enemy positions".

Each class has a set of special skills unique to its kind. One of these is unlocked at level 20, and is usually the best skill available. The Assault's special skill is "Assault Team", which calls in a team of soldiers to drop in the game and fight for 15 seconds. The Medic's special skill is "Zombie Antidote" which does large damage to zombies in a large area. The Heavy's special skill is "Aerial Bombardment" which is an air strike in a selected area.

When first creating a character, you receive 2000 SAS cash to purchase gun augments, turrets, or grenades. You receive a strongbox each time you level up, giving you either new gear or a new weapon. You also receive more cash. Another difference is that players now collide with zombies and can't run through them. This may sound benign, but actually fundamentally changes the game, making the actual zombie fighting more skill-based, and also makes the game more tactical.

Trivia

 * SAS: Zombie Assault 4 is the first SAS game out of the series to have a science fiction setting.
 * The game is also the first in the series to have actual characters, minus the one scientist found in the Zombie Assault 3 Bamboo Thicket map, though the scientist didn't have a name.
 * It is also only version to have all weapons unique.
 * In Zombie Assault 4, the first mission has you defend the ramps with blast doors being like barricades, that you cannot repair, from the first three games, with the final mission being similar to a tower defense like.
 * Unlike previous games, where you buy guns in stores along with armor, you actually have to find guns and armor in strongboxes found in secret areas or by killing a certain kind of bosses or, rarely, regular zombies,
 * Missions in Zombie Assault 4 are unlocked like the regions in the mobile version of Zombie Assault 3: the player has to be a certain rank or higher before they can start them.
 * Once at Rank 20, players of the Assault class unlock a skill that calls forth A.I. buddies, similar to the Buddy of the mobile version of Zombie Assault 3 but armed well and disappears after certain amount of time.
 * The Assault class SAS is shown holding a RIA 20 Striker, while the Heavy Class is holding a HVM 008 and a Medic Class SAS is holding a CM Gigavolt.
 * Despite being in the year 3104, the SAS still has some weapons that resemble modern-day weapons.
 * Unlike previous games in the series, Zombie Assault 4 has its own unique ranks and insignia.
 * There are 7 unique skills for each class.