Alien Hallway Achievements Here is the full list of all 20 Alien Hallway achievements.Filter Achievement View View Image viewList view Sort by TrueSteamAchievement desc TrueSteamAchievement asc Achievement name desc Achievement name asc TSA Ratio desc TSA Ratio asc Gamers desc Gamers asc Steam order Date won desc Date won asc What are achievement flags? Click to find outApply LiberatorComplete all game levels Blood LustKill 100 aliens BloodbathKill 1000 aliens Good startLiberate the first planet ArmadaCall for 50 friendly units Numerical SuperiorityCall for 20 friendly units during the battle SpecialistUpgrade one unit till 10th level Air supplyUse airstrike 100 times Fire in the holeThrow 300 grenades PerfectionistGet 5 stars for all game levels InvincibleComplete any level of the last planet without loss of friendly units Master of defenseUpgrade the base till 5th level 1 guideAir forceUpgrade airstrike till 7th level Elite only!Call for 5 Heavy laser gunners during the battle HellCall for 20 Flamethrowers during the battle MeanAccumulate 1000 energy units during the battle (can't be achieved on "Resources refill" and "Final Step" levels) ExtremeWin the battle with lower than 50% health level of your base 1 guideGreat commanderUpgrade all friendly units till 4th level ProfessionalComplete the game on extreme level of difficulty Phantom warriorHave 10 Snipers simultaneously present during the battle