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The UFO: Alien Invasion Game Guide

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ANDR01D writes PC game reviews and shares his views on the video game industry.


Lately I’ve been playing the freeware open source title known as UFO: Alien Invasion. There was probably a lot of stuff that I didn’t include in the review I wrote of said game, and that stuff I thought would be perfect to have here in this guide to playing UFO: Alien Invasion, with lots of helpful tips and tricks learned while playing the game.

Geoscape mode

  • When it gets near the end of the month and you are due to receive funds from all the nations, make sure to dismiss scientists, pilots and workers who aren't working, and soldiers who aren’t… soldiering. Otherwise their salaries cut in to your monthly upkeep and admin costs and that’s a waste. You could even dismiss all workers, scientists, pilots and soldiers and just rehire them in the new month, if you’re feeling very scroogey. This would be much easier if you could save soldier weapon and gear loadouts, but you can’t for now.
  • In version 2.5 (unreleased at the time of writing) this is especially important seeing as higher ranked soldiers are paid more. But you likely won’t have them sitting around if you’re smart anyway. You’ll have them out in the field.
  • Every base should have at least two heavily armed and armoured interceptors ready and primed to take on enemy UFOs.
  • Preferably, you should launch Stiletto interceptor aircraft when UFOs are within the radius of your base’s SAM defences. Only use Saracens for long range combat, because they have more fuel and are faster. The downside is they aren't as accurate and are weaker against enemy fire.
  • You can launch interceptors or even dropships to lure fighter-class UFOs near your base and SAM site installations. Then when they get close you can either attack them or make your interceptors return to base and let your base defences take the UFOs down.
  • Shooting UFOs down over the sea has pros and cons. Yes, you don’t have to engage the aliens on board in combat, but you also don’t have a chance to capture aliens and their technology for research.
  • A base should be surrounded by at least two or three SAM sites, all with overlapping radii of fire. Don’t leave any gaps in between.
  • This goes for building bases too. You should have bases’ radar signals overlapping so as not to allow UFOs to slip through any gaps. If there are any areas that are not covered, you can build standalone radar installations.
  • Make sure to research laser weapons which will give your troops a better chance against the aliens, and to better defend your base as well.
  • Always have enough labs, living quarters, and scientists to research alien technology, and then put the knowledge acquired to good use by producing new items and weapons for your base, aircraft, and soldiers. You’ll need a workshop to carry this out.
  • A new base’s starting rooms should include a command centre and a power plant. All future rooms and features are dependent on these.
  • You should strive to have a base on every continent. This will reduce response time when aliens land in an area. And the quicker you get somewhere the better, as the nations don’t like the aliens hanging around for too long. UFO terror sites and crashes even have a chance of disappearing if you take too long to respond.
  • You can save on production and purchase costs by using the transfer feature, sending items from an oversupplied base to an under-supplied one.
  • While you can sell alien weaponry and armour to make money, make sure to keep at least one of each type for research purposes. The same goes for UFOs.
  • Keep completely intact UFOs in your UFO yards, and sell the damaged ones that have been shot down.
  • Later, when you start using alien weapons, keep as many as the squad needs of each weapon and sell the rest.
  • You should keep the ammunition you find for each alien weapon initially. At least one to be used in the weapon, one as a backup for reloading, and another when you need to restock ammunition after a mission. Because they can’t be produced in the workshop without the necessary alien materials.
  • This is why even though it is tempting to sell UFOs, often to the highest bidder, which does have some pros like boosting a nation’s happiness and of course a quick cash injection, it might behove you to store some UFOs in a UFO yard, and disassemble them instead so you can get a hold of some alien materials.
  • You might consider transferring some veteran soldiers to other bases to accompany less experienced recruits on missions, seeing as veterans perform better in missions with the benefits of higher stats and more time units. When they reach the rank of Sergeant (usually a squad leader) or Warrant Officer, consider doing this.
  • Some people like to have classes of soldiers. They'll have snipers, medics, support gunners and basic infantry units, all with different gear. So it’s sort of like Team Fortress 2. But I, apart from giving units different weapons and ammo, prefer to standardise their weapons loadout. Every unit has IR goggles, medkits, grenades (frag and plasma), flashbangs, smoke grenades, incendiary grenades and so on. This way I don't have just one or two guys on a team that have a medkit who can heal others. What if they die? Then nobody has a medkit, unless someone retrieves it while on the field.
  • There are several weapons available to your squad. You should use as many as possible. Have two or three soldiers with assault rifles/laser rifles/plasma rifles; one with a riot shotgun; one with a light machine gun/heavy laser/plasma blaster; one with a grenade launcher/rocket launcher; one with a sniper rifle; and one with a flamethrower. Any remaining troops can have assault rifles/laser rifles/plasma rifles.
  • Arm units with small secondary weapons that can be used in the left hand when either in close quarters combat, indoors, or when you run out of ammo for your primary weapon.
  • Pistols, laser pistols, alien pistols, and machine pistols are good for secondary weapons, while micro shotguns and submachine guns cannot be used with one hand, namely the left, forcing you to drop your primary weapon, which will cost you extra action points in order to pick it up.
  • The best melee weapon available would be the plasma blade. It’s a one shot one kill weapon. Don’t bother with combat knives or even alien swords. The latter takes up too much space in a unit’s backpack.
  • While it may be appealing to hire a recruit that has, for instance, a high sniper rifles skill, and lower skills everywhere else, it’s probably better to hire someone who is more of an all rounder. They’ll still progress just as well if not better, at sniping or whatever other purpose you have in mind for them. All skills go up slightly after a while.
  • Save often, using regular saves and quicksaves (F5 key for PC). Always save before and after every mission, especially if you opt for the auto complete feature. Because very often the results won’t be to your liking, which is why it is not recommended.
  • When distributing newly produced armour, don’t wait for the entire batch to be produced. You should start handing them out as they are produced. Always make sure your assault units are heavily armoured. Snipers can perhaps afford to be lightly armoured for longer seeing as you wouldn’t put them in to a close quarters combat situation if you could help it.
  • When troops sustain minor wounds, there’s no need to remove them from a squad assigned to a Firebird. There’s a good chance they’ll heal before the next mission as long as they are admitted to the base’s hospital. Only do this when they’ve sustained medium or major wounds, and then replace them with new recruits temporarily. Sending heavily wounded troops in to combat isn't a good idea as it really does detract from their combat efficiency, meaning they'll probably stand a better chance of dying.

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Battlescape mode

  • If your squad lands in a hot LZ, it's best to use a few action points to try to take down the aliens, rather than travelling long distances to reach cover, or retreating. Because aliens, if facing in your direction, will take this opportunity to interrupt your move and try to shoot you. If they aren't facing you, then make a break for cover.
  • Don’t let units stand out in plain view. They should only do this when breaking cover to take a shot at the enemy. Otherwise, have them behind cover.
  • Remember to use the crouch feature to make your units harder to hit, particularly from a long distance.
  • Crouching can also improve your unit's accuracy.
  • Always leave enough action points for crouching and taking cover. You can set this to happen automatically.
  • Don't let too many civilians die and especially don't kill them with friendly fire. The nations won't be impressed and their disposition will tank. Units who kill civilians will not reach high ranks.
  • Don’t ever let your more experienced troops die. They are worth a lot more than new recruits. Hit that retry button if they die.
  • If you have something risky or dangerous in mind on a mission, send a recruit, or a low ranked soldier if you must, to do it. If they die, it’s not as big a loss to you.
  • Taking one or two new recruits on missions has its benefits, because they’ll gain experience – if they don’t die, that is. Then you’ll have more experienced troops in your employee pool to assign to new bases.
  • Always have the maximum amount of troops allowed in a mission. You have the Firebird which is capable of taking 8 units to a destination (12 in version 2.5). There’s no point in being outnumbered, because you stand more chance of failing the mission.
  • Try to flank enemies if you can. Have some team members engage the enemy, and others get on their flanks so you can surround them and attack from multiple directions and hopefully catch them out in the open.
  • Use grenades when there are two or more aliens in close proximity. Even if you don’t take them all out, some will be injured.
  • You can also use grenades to flush enemies out who are behind cover or indoors.
  • Hold your fire if civilians are in the way, between you and the enemy. You can’t risk killing them in the crossfire. The aliens might kill them, but at least you won’t. This would be bad for Phalanx public relations. This is especially crucial when using units with explosive weapons or weapons that utilise burst fire.
  • Be sure to not have other units in the line of fire either, otherwise you risk injuring or killing them with friendly fire.
  • Heal your units in the field with medkits before the mission ends – this will save you having to contend with having your best units out of action in the hospital for days or weeks.
  • Always comb the outside or perimeter of the map, before heading indoors. Sometimes one can spend a lot of time hunting for aliens indoors and all the while they were hanging out on the front lawn.
  • During base attack missions, keep in mind that the two entry points to your base will be the entrance (obviously) and also the large hangar. The aliens will start off topside and make their way to these entrances.
  • Never send snipers first in to close quarters combat situations. They aren’t suited for it. When moving forward, assault weapons specialists and flamethrower guys should go in first, covered by the support gunner and heavy weapons dude. The snipers should either maintain their distance or bring up the rear.
  • Make sure to make snipers and especially heavy weapons guys select their secondary weapons in close quarters situations, especially indoors. You don’t want a grenade or rocket going off in close proximity and wiping out the rest of your squad.
  • Very rarely does it pay to take a shot if you don’t have a clear line of sight. If the line of sight isn’t green at least 95% of the way to the target, reconsider taking the shot. It’ll just be a waste of time units. Firing blindly or providing suppressing fire has mostly no effect on the enemy.
  • If you’ve cleared the map of all aliens but the mission has not yet ended, chances are the last aliens are aboard the UFO, if it’s still whole (as in not damaged during the crash).
  • You can’t always see aliens, but you might hear their weapons fire or footsteps. This might give you an indication that they are nearby.
  • If civilians all gather in one area, or don’t move much during rounds, chances are those areas are clear and you can continue your search. If they are running around frantically or getting slaughtered, then it means aliens are in that area.
  • Always move from cover to cover. If there is no visible cover, then create some with smoke grenades.
  • Flashbangs can be used to stun aliens and also civilians – to stop them from getting in the way or getting killed. Aliens won’t attack civilians who are unconscious, because they probably think they’re dead.
  • Flashbangs have the effect of taking away an alien’s reaction fire ability or consuming all their action points in the next round. This is great if you're caught out in the open, perhaps ambushed by more than one alien.
  • Burst fire mode is great when up close and personal.
  • A snapshot is “firing from the hip”, not an aimed shot. Snapshots might be worthwhile at close range.
  • The colour camouflage you wear currently (as of v 2.4) doesn't have much effect on your visibility so don't waste time trying to dress appropriately. In later versions it might have more of an impact.
  • Don’t lob grenades (or use timed grenades with the grenade launcher) directly at an enemy. Aim a bit before him, otherwise the grenades will bounce past and miss. This is especially true if the alien is near the edge of the map.
  • Make sure to have soldiers look in a direction before shooting. There are some situations where an alien becomes visible to one or more of your units onscreen and you turn to shoot, and you haven’t yet seen the civilian in the way, and they get hit instead of the alien. You should spend a time unit to look first, and then shoot. Unfortunately, enemy units and civilians are only visible through the eyes of your units. The entire map is not revealed in its entirety.
  • Soldiers should be close enough so that they can heal other nearby soldiers, or trade items if necessary, but make sure to keep a good spacing of at least a few blocks on the grid. You don’t want one well-placed plasma grenade taking out an entire squad.
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  • If there’s not enough cover on the map starting out, you can always use the Firebird as cover.
  • In fact if there’s not enough cover and you think one of your units will be too exposed while crossing terrain, then rather stay behind available cover and end your turn. There’s a chance that the aliens might make the first move and cross the virtual “no man’s land”.
  • Be careful though, because if there’s too long a period of inactivity, and you aren’t keeping the aliens occupied by fighting them, they will actually force you to make a move and draw you out, by killing civilians. Bastards.
  • If you run out of ammo during a mission, you can pick up ammo from fallen soldiers, and also from dead aliens. As long as you’re able to use these weapons and ammo, you should be fine. They need to have been researched first, otherwise they are effectively useless to you.
  • If you have a unit that is close to an alien and will be in his field of view if you come out from behind cover, say a corner of a building, chances are if you try to shoot it, it will damage you with reaction fire. Preferably you should try to take the alien down from an angle with a grenade’s splash damage, or flank the alien with another soldier.
  • Make sure to cycle through each soldier to make sure you’ve used up their time units before ending a round. It could mean the difference between winning and losing, or at least the life of a soldier.
  • If you are out of grenades, or you are too close to your enemies and risk getting caught in the blast, there is the possibility of gaining two kills with burst fire from an automatic weapon, which won’t damage you in the process, as long as the aliens are in close proximity. Just make sure one of your units is in the same area when you fire, otherwise they risk getting hit and possibly killed.
  • It pays to have all your units covering one another, watching every direction and every entrance. This way it makes it harder for aliens to sneak up on you. This is especially important when first disembarking at the LZ.
  • Review: UFO: Alien Invasion
    I take a look at UFO: Alien Invasion, a freeware game inspired by the original X-Com title, UFO: Enemy Unknown.

© 2013 ANDR01D


brian harveson on June 07, 2017:

About Interceptors:

I think you can skimp on interceptors by installing at least one SAM site (external) and at least one Laser module (internal), with another SAM site (external) 'on the other side' of the base location. This really knocks the stuffing out of Harvesters, but later craft (Gunboat, Corrupter, Bomber) are tougher.

It's a bug of sorts but a faster interceptor can 'lead the aliens' around the air-defense-zone until the missiles and laser shoot it down.

Using re-searched particle-beam weapons and alien missiles brings the craft down with fewer systems destroyed and the alien crash has almost all the hardware intact.

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