Release notes 0.6.23:
-Receive extra money when killing zombies with headshots and melee
-Increase money rewards on easy difficulty
-RAPID REFLEX perk increases movement speed by 5%
-Potentially fixed the hang when starting up the game
-Increase the slowdown that BARBED WIRE applies to zombies by like 50%
Release 0.6.23
Source: Steam Community (opens in a new tab)