If we're talking about the one on newgrounds, then this is what you do.THE REACTOR
Marine order: The three pistols *P*(Hudson, Frost, and Crowe), the two smartgunners *S*(Vasquez and Drake), the flamerthrowers *F*(Dietrich and Werzbowski), Hicks*H*, and then Apone*A*.
Organize them in the bottom left corner of the red start box like this: (Letters represent Marines and - is a pillar)
Move everybody straight ahead towards the exit. Number one rule of surviving a xenomorph encounter: NEVER go anywhwere alone! Keep them together. This way, you can attempt to throw off any xenos that grab you. This mission is possibly the hardest due to it being entirely luck based. Xenos can and will drop down on top of you without warning. Do NOT use the flamethrowers to kill the xenos on top of any marine, you will kill them too! I hardly ever try to shoot any xeno on any marine due to the acid splash damage. You'll end up using the smartgunners a lot to pick off xenos from a distance, but don't let them fall too far behind. Use Hicks and Apone to cover the rear with their 3 turn action phase. Protect the pistol marines, they may be useless now, but they are better in Operations.
Always plan out your and the Xenos movements. Except for Hicks and Apone, you can only move 2 squares per turn. Xenos can move 4 squares per turn. Before moving, always see how far a xeno can go on its next turn. Shoot any xeno that is in the "kill zone" before moving into it. When moving, always leave at least one square between you and the xeno's range of movement. This way, you can kill any xeno without having to worry about acid damage. Apone, Dietrich, and Werzbowski can break this rule because they have flamethrowers, but make sure that they are the ones that kill any adjacent xenos or you risk acid damage. Though Hicks has a good ranged weapon, he has less ammo than anyone else. Only use his shotgun if he has at least a 70% chance of killing a xeno, 60% if you are willing to risk wasting a shot.
Watch out for xenos using corners as cover. Stay out of their reach and what for them to come into your range. You may have to restart the game over and over many times before you get everybody through alive. It's hard to do, but you can do it.OPERATIONS
Marine order: Burke(AI), Newt 1
, Ripley 2
, Hicks 3
, Dietrich and Werzbowski 4 and 5
, Gorman 6
, Vasquez, Hudson, and Crowe 7, 8, and 9
, Apone 10
, then Drake or Frost 11 and 12
Organize them like this in the red starting area: (Numbers are the Marines,  is a pillar, and X is empty space.
X- X- X- X- X- X- X
X- X- 6-12-10-11- 5
X- X- X- 9- 3- 2- 4
X- X- 8- 1
The next to missions are a little bit easier, if you know what you are doing.
For the first three turns, the xenos will apear in the top left corner. Move Newt two spaces to the right so that she is directly beneath Ripley. Then have Ripley shoot two gernades two squares into the room to the south so that the shockwave with knock out Burke. This way, you don't have to worry about him locking the door. Be careful, it might knock out Newt also if the gernade lands one square too close to her. Next, have Hicks step down beside Newt and then shoot what he can. Dietrich and Werzbowski are useless, so keep them to the side. Gorman is a meat shield because he only has a pistol and doesn't have a torch. Kill any xenos that you can with Vasquez, Hudson, Crowe, and Apone. Use Drake and Frost to kill any xenos that get within the acid splash zone.
For turns 4-6, the xenos appear at the top of the screen. If you can, move the marines as close to the hallway as you can.
On turn 7, you can start to head towards the door. Remember to keep Ripley next to Newt at all times. Pick up (or not
) Burke on your way out. You'll want Hicks to do be near them to keep them safe. Get the pistol marines out of there immediatly.Watch out!
On turn 8, a xeno will drop down in the red starting zone and may grab a marine. Priority one: get Newt into the next room. Alternate between the marines 7-10 with shooting and running. Have marines 11 and 12 cover your rear with the flamethrowers.
On turn 10, Newt will point out the air vent. KEEP THE MARINES IN ORDER! You do not want a traffic jam in the air vents just because they are out of turn order. Have marine 12 seal the door behind you.
You should now be around turn 15. Continue through the air vents and pray that Newt remembers the way and doesn't get you all killed by stalling. Heads up!
Around turns 22, 26, 29, and 34, xenos will drop down around the 1/5 marks of the air vent. Around turn 28, the door will break and xenos will start flooding in. Use marines 11 and 12 to kill xenos with their flamethrowers and to make flame barriers.RESCUE NEWT
Marine Turn Order: Ripley 1
, Hicks 2
, Vasquez or Drake 3
, Dietrick, Werzbowski, or Frost 4
, Apone 5
, Vasquez or Drake 6
, Hudson, Gorman, or Crowe 7
, and then Dietrick, Werzbowski, or Frost 8
Organize them like this in the red starting area:
8- 7- 3- 4
6- 5- 2- 1IMPORTANT!
You only have 50 turns to complete the mission before the place blows up! What I like to do is kill the queen. She likes to hide in the rooms to the south of the elevators. Have Ripley use a gernade to try to flush her out. Shoot the gernade through the stairwell and into the second room, that usally works. If it doesn't, move on a pray that she doesn't turn up later.
If it does work, take a defensive postion like this: (E is Elevator Space)
E- E- E- E- X
E- E- E- E- X
X- X- X- X- 4
X- X- 7- 6- 3
X- 8- 5- 2- 1
X- - X- X
Use 1, 4, 5, 6, and 8 to create flame barriers when nessicary. Remember, the queen can move 3 spaces and kill multiple marines within one space of where she stops. She takes nine hits to kill. When she is dead and you have a break between the waves of xenos, move on. Mind your distance when moving near stairwells, for thats were xenos spawn randomly on the map. Use the tracker to where Newt is. Use the hallways as much as you can, for xenos will start to drop down in rooms that you enter for the next three turns or so. However, the hallway in the north will blow up after you found Newt, so you'll have to go through the rooms to reach the exit.
When you reach a door to a room, make sure everyone is one space away from the door. Have Ripley take one step in then two steps out. When you need to (and believe me you will) use firebarriers to block a doorway so that xenos won't kill you as they rush you. After you fend them off, press onward. Remember to watch your ammo and stay together. You might want to place a pulse rifle, a smartgun, and a flamethrower in the room located 12 steps from the top and 12 from the left so that it can snipe xenos from afar with the smartgun and gernades. Use flamethrower for close quaters. Get Newt and get out!