After the End/Mechanics

Mutant spawning
The monster spawning mechanics on this game are quite simplistic and can be bent for experience gain purposes
 * Mutant Count - Almost all levels in this game both for Campaign and Firing Range exhibit a total mutant count, if the player so chooses to stay on a level even if the finishing requirements are met and decides to kill more monsters, mutant spawning will keep on going until the mutant count is finally exhausted causing no more mutants to spawn or appear anymore, this is not recommended on Firing Range due to having low ammo count and capacity but absolutely recommended in Campaign.


 * Required kill count is different to total mutant count, assuming that a level for example requires 200 mutants to be killed before it is finished, the total monster count could go all the way to 350, if you killed 200 mutants and the requirement is already met, you can still kill the remaining 150 mutants before the level is completely empty and then you can finally go.


 * Mutant Spawner - A Mutant Spawner is like an exhaust looking spot where mutants could spawn from, mutants spawned from these spots are not probably counted towards the total monster count but these are good sources of experience points for the player too, as these spawners will keep on producing monsters until they are destroyed, Mutant Spawners can spawn different mutants and the only way to distinguish which one produces which is to wait for them to be active and see what they produce.

Environmental properties
These properties could be potentially risky to you as it could kill you except the Electric Towers, but these are also risky to all mutants as well except the Avian Mutant but it will die to Electric Towers, all mutants these properties kill except the Deactivated acid counts toward your score, kill count, and probably experience gain as well.
 * Acid - This fluid has a normal green color, and stepping on this will cause damage along with movement reduction.
 * Deactivated acid - A variant of acid where the fluid instead has lighter green color, stepping on this will not cause damage but it will still reduce movement speed.
 * Lava - This has an orange color, and it will light up the place during dark or reduced vision levels, stepping on this will reduce movement speed as well as inflict damage.
 * Railroad train - Exists in railroad levels, an indicator that a train will cross is by looking at the lights, if the lights along the railroad are blinking then you shouldn't cross first, anyone who gets caught in the path of the train will die immediately, you will also die to the train even if you are riding a tractor.
 * Electric towers - These towers will not target the player, only mutants, they deal good amount of damage to mutants that sometimes they can kill mutants on their own, on selected levels these towers could be permanently deactivated, temporarily deactivated which means you have to flick a switch to activate them, and already activated which means they are already active.