Go to left and take Ration Pack and go right to take the other ration pack (you will use them later) and go forward twice and take hunting rifle and ID card and go forward and use sniper rifle to kill those 5 aliens and look at your inventory and use the ration pack [this will restore your health to FULL health (don't use this when you are in full health because when you used this WHEN you are in full health,you just wasted a ration pack)]. Go forward and take ration pack and go forward twice and take ice axes and go up the mountain and climb up the mountain (right, left, right, left, right, left, up. Kill the 6 aliens and use one ration pack and go to the observatory and make sure that the color patterns on the left and right are same.

EXAMPLE:

When one color is red, here are the colors AFTER red everytime you click it. Green, blue, yellow, red and so on and so on but you can only click the hexagons on the right side.

Do this for 3 times and you're in the observatory. Go right and take ration pack and go left and take ration pack and click comms lock 4 beside the communications room and click the lock on the data storage room and you will see a number above (Hindu-Arabic form) and there are 4 hexagons with roman numerals 1-6 and make sure you rotate the hexagons and make sure each number (Roman Numeral) is facing at the line pointing to the center and make sure that when you add every number pointing at the line, the result should be same with the number at the top. Do this for 5 times and go to the data storage. You will get USB stick (read Edgar's comment on how to use it) and click Comms Lock 2 and open window and kill 5 aliens and use 1 ration pack and get out of there and go to right and click the lock on the Maintenance Room and open Comms Lock 1 and 3 and go outside the window and kill 5 aliens and go back and get out and go to Communication Room and use the radio and get out of the observatory and you will see a U.F.O above (doesn't give you any points for clicking it) and kill 7 aliens and the U.F.O. will leave and there are the Army Choppers on the way and once they're here, get in the chopper and one of them will say-"Throw him on the brig...along with his 'Friend'". And once you're on the brig, you will see your 'friend' who's an alien and he will say "Help me...Human!" and go to him and... THE END!