Here is the full list of all 35 The Lord of the Rings: The Battle for Middle-earth II achievements worth 705 gamerscore.
Complete Good Campaign without a Hero dying Hero: Mektar
Complete Evil Campaign without a Hero dying Hero: Urulooke
Lose 10 Multiplayer matches in a row
Win 10 Hero Vs Hero games Unlocks Hero: Felek
Win 10 Resource Race games Unlocks Hero: Celebrim
Win 10 Capture and Hold games Unlocks Hero: Avatan
Win 10 King of the Hill games Unlocks Hero: Fhaleen
Win 10 Versus games Unlocks Hero: Ohta
Win a game against someone 20 places higher than you
Win 1 Resource Race game
Win 1 Capture and Hold game
Win 1 King of the Hill game
Complete Evil Grey Havens with all bonus objectives (Level 2)
Win 1 Versus game
Complete Good Celduin with all bonus objectives (Level 6)
Complete Good High Pass with all bonus objectives (Level 2)
Complete Evil Rivendell with all bonus objectives (Level 8) Unlocks Hero: Olog
Complete Evil Campaign Unlocks Hero: Tumna
Complete Evil Erebor with all bonus objectives (Level 7)
Complete Evil Withered Heath with all bonus objectives (Level 6)
Complete Evil Mirkwood with all bonus objectives (Level 5)
Lose to someone ranked 20 places below you
Complete Evil Fornost with all bonus objectives (Level 4) Unlocks Hero: Thrugg
Complete Evil Shire with all bonus objectives (Level 3)
Complete Good Blue Mountains with all bonus objectives (Level 4) Unlocks Hero: Maur
Complete Evil Lorien with all bonus objectives (Level 1) Unlocks Hero: Krashnak
Complete Good Dol Guldur with all bonus objectives (Level 8) Unlocks Hero: Idrial
Complete Good Campaign Unlocks Hero: Berethor
Complete Good Erebor with all bonus objectives (Level 7)
Complete Good Grey Havens with all bonus objectives (Level 5)
Win 1 Hero Vs Hero game
Win 1 Single Player Skirmish game
Complete Good Ettenmoors with all bonus objectives (Level 3)
Complete Good Rivendell with all bonus objectives (Level 1) Unlocks Hero: Hadhod
Purchase first player power