SAS 4

SAS 4 is a flash game made by Ninja Kiwi. The game has many pieces of armor, many guns, 2 campaigns, and much more. The game was released on mobile after the flash version was released and the only way to play the flash version is by going to Ninja Kiwi Archive because the flash version has been discontinued as of December 2020. The game also has co op  and there is private matchmaking so you can play with your friends. There is also nightmare mode and contracts, and for contracts you do some sort of mission and you gain awesome rewards and for nightmare the zombies are even more stronger and there are black keys and black strong boxes that you can get in nightmare mode. Plus, the black armor and weapons are even more stronger and there are elite augment cores that you can put on your weapons and armor to make them even more awesomer and nightmare mode is unlocked at level 35. What could be bad about that? Well apart from the harder zombies...