Alien Hallway achievements

Complete the game on extreme level of difficulty

Win the battle with lower than 50% health level of your base

Upgrade one unit till 10th level

Get 5 stars for all game levels

Upgrade the base till 5th level

Complete any level of the last planet without loss of friendly units

Upgrade all friendly units till 4th level

Upgrade airstrike till 7th level

Complete all game levels

Use airstrike 100 times

Have 10 Snipers simultaneously present during the battle

Call for 5 Heavy laser gunners during the battle