Chapter 1: Prologue
Status: found
Chapter 2: Somplace Else
Status: Fully lost
of2_xen (all maps)
Chapter 3: City 14
Status: Partially lost
of2_c14_03 and+ (Sniper and clocktower)
Chapter 4: Dark Passage
Status: Partially lost
of2_sewers_03
Chapter 5: Outlands
Status: Partially lost
of2_outlands_03 and of2_outlands_04
Chapter 6: Underground Complex
Status: Partially lost
of2_uc_office3
Chapter 7: Broken Communication
Status: Partially lost
of2_brokenc2
of2_brokenc3
Chapter 8: Forestral Ambush
Status: Partially found
of2_forest_02 and +
Chapter 9: Cold Adaptation
Status: Fully lost
of2_caves01 and+
Chapter 10: Phoenix Hideout
Status: Partially found (only 1 map of2_superportalxen)
of2_camp01 and+
Chapter 11: Channeled Assimilation
Status: fully lost
of2_apc
P.S. There are still wallpapers on which you can see a screenshot of Channeled Assimilation
Bonus: OF2 Capture the flag:
Fully found
of2_ctf
of2_crossfire