Added new version map - v.4b
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-Removed all ventilation
-Number of props significantly reduced
-Zombie respawn now occupies the whole area of the rail
-Teleport for 2 spawns activated from 2 waves
-Zombie gas at 2 spawns increased
-The teleport indicator for 2 spawns has been changed to a brighter one, and another teleport has been added to the center
-Added passage between toilets

Added new version map - v.4a
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-Added a new spawn (teleport) for the zombie, which opens on the 4th wave.
-Some rooms are enlarged in size
-Changed the usual zombie spawn
-Added ventilation from spawning zombies to the middle of the main large corridor
-Ventilation in the toilet is now available only for headcrabs (maybe for zombie torsos)
-Minor changes

Added new version map - v.4
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-Toulets completely redone
-The shop is redone
-Optimization
-Some rooms are extended
-Added some decorative effects
-The ventilation passage between the security room and the station is removed
-Other minor changes

Added new version map - v.3