Onslaught

Onslaught is a type of mission where you have to eliminate all waves of zombies. It is the only mode in earlier versions of SAS: Zombie Assault series.

SAS: Zombie Assault 3
In SAS3, it is the only mode available in solo play. You'll have to survive against 3~8 waves of zombies in a map. The player(s) will be awarded some health after each wave.

SAS: Zombie Assault 4
In SAS4, it is the first mission available and also the mission the new player starts in.

Plot
A dropship in an infested space station cannot depart because its door ramps are stuck. The player(s) must survive and kill all zombies for 5 min.

Layout
It's a dropship with door ramp on right, a large room with boxes in the middle, and side passageways on top and bottom of the central room.

Loots

 * After 3 minutes, the pilot will drop 2 loots each on each passageway of the map, just outside the central room
 * After 4 minutes, the pilot will open door to the forward jump seats where there's a loot and a medipack.
 * between the 2 barricades the player must defend, there's a black area which can be opened by shooting at it from right, which will drop a loot and a medipack.

Tactics
In start of the game, try double-blocking the both entrances with both boxes because it's most likely that the barricades will fall. When the boss comes, fall back to the forward jump seat(all the way to the left) and force the boss in a circle. If the boss is necrosis or contains necrosis, try running around the whole map dodging and try killing the teleporter first. It is also important to destroy the tall boxes in the middle area which will just get in your way when bosses comes.