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It was bound to happen. A group of hackers uncovered some of the secrets of the Halo 3 beta, including the achievements list and a few assorted goodies. The lines in the code suggest that some achievements are based around the popular skulls from Halo 2, some are online accomplishments, and some come from completing stages.
Here is the code list.
- achievement_complete_mission_jungle
- achievement_complete_mission_base
- achievement_complete_mission_outskirts
- achievement_complete_mission_voi
- achievement_complete_mission_floodvoi
- achievement_complete_mission_wasteland
- achievement_complete_mission_citadel
- achievement_complete_mission_highcharity
- achievement_complete_mission_halo
- achievement_complete_campaign_easy
- achievement_complete_campaign_normal
- achievement_complete_campaign_heroic
- achievement_complete_campaign_legendary
- achievement_find_outskirts_skull
- achievement_find_voi_skull
- achievement_find_floodvoi_skull
- achievement_find_waste_skull
- achievement_find_citadel_skull
- achievement_find_highcharity_skull
- achievement_find_halo_skull
- achievement_jungle_training
- achievement_jungle_no_casualties
- achievement_floodvoi_no_flood_victims
- achievement_spartan_recruit
- achievement_spartan_graduate
- achievement_spartan_officer
- achievement_extra_crispy
- achievement_banshee_surface_to_air_kill
- achievement_triple_kill
- achievement_killtacular
- achievement_sticky_x5
- achievement_brokeback
- achievement_tripmine_vehicle_kill
- achievement_flag_carrier_kill
- achievement_kill_frenzy
- achievement_triple_sword_kill
- achievement_mongoose_splatter
- achievement_melee_kill_x5
- achievement_needler_kill_x5
- achievement_sniper_kill_frenzy
- achievement_headshot_kill_frenzy
- achievement_full_warthog_kill
- achievement_temporary_placeholder