Visual bugs, such as the missing "Multirocket" attachment graphics, were resolved. :

: New destruction visuals for Beheaded Soldiers and male Gnaars.

: Enhanced "gore" and destruction animations were added for specific weapons and enemies.

Corrected a level-specific bug in "Kleer Fortress" that prevented the difficulty from resetting to Normal after a restart. Serious Sam: Siberian Mayhem on Steam

Released on August 1, 2022, Update 1.04 introduced significant refinements to both visual feedback and quality-of-life mechanics.