Each turn is split down into a total of nine different phases, going from the collection of income, investments for research and production over to diplomacy and UFO missions. During these missions the players have to use military forces to stop the aliens either in their approach or in a ground battle, and after all UFOs have been dealt with the players' units finally return to their bases for the end of turn phase in which victory conditions and research results are checked.

As indicated, the income of the players depends on the number and wealth of the countries siding with the alliance, and the players may increase their income by recruiting more countries to their side. Such recruitments may be made in the diplomacy phase where the players have to decide on one country in which a diplomatic mission is made, and two dice are rolled in order to see whether the diplomatic mission was a success. Depending on the size of the country, a certain result must be rolled, but if the alliance successfully gathers a growing number of countries to its side this dice-roll will receive a positive modifier because the unanimity of the alliance-siding countries will make it easier to sway the opinion of the government of the country which is target of the diplomatic efforts.

The aliens on the other side will not waste time on diplomacy - they want to impress by force. Thus, they will try to pierce the alliance defenses by use of UFOs, and whenever an UFO reaches a target country a dice-roll is made and modified by the size of the attacking UFO. Similar to the diplomatic approach of the alliance, a certain result must be rolled, and a success will mean that the country sways one step towards the alien side. (I.e. alliance-siding countries become neutral, neutral countries go over to the alien side). Whenever a country joins or leaves one of the warring parties, both the alliance income and the current levels of victory points of the alliance and the aliens need to be adjusted according to the country's value, and it is the players' collective aim to end the seventh round with more victory points than the aliens.

Returning to the alliance income, the players can spend this money on collective research and on building their individual bases and forces. Thus, after the income is collected at the beginning of each turn, the players can decide to invest money to research a new technology, but as a nasty twist the technology does not become available right away but instead the players have to wait till the end of the round to see whether their efforts were successful. The result of research is not based on luck, but instead the players will have to possess a number of laboratories as required by the researched technology. Furthermore, the more advanced technologies require the players to possess knowledge about the aliens, and such knowledge only can be gathered if the players successfully battle alien invasion forces.

Three of the four technologies available for research deal with the different types of troops available to the alliance: Fighter jets, tanks and infantry squads. The higher the research level in each category, the better will the units of all players perform in combat. There is no need to update troops, since all kinds of units automatically are considered to be updated to match the current research level. However, to build up a military force, a player first has to invest in his base, since the purchase of any type of unit (fighter jet, tank, squad) first must be preceeded by the purchase of a matching base building. So, the players need to purchase hangars, garages and barracks where there units can be placed, and as a further prerequisite the maximum number of buildings for each of these categories is limited by the number of warehouses a player has added to his base.

The money to make individual purchases comes from a player's starting allowance, and furthermore the part of the alliance income which was not spent on collective research is equally shared between all players. This money can be used to improve the players' bases and purchase military units, and the players then can use their military in their valiant defense of Earth.

The military campaign develops the same way during all seven rounds. First, new target markers are drawn from the container with the markers of the neutral and alliance countries and the player bases, and then an approaching UFO is drawn for each of the drawn targets. The UFOs also come from a container, but the composition of this UFO container will change during the course of the game since ever-stronger UFOs will be added to the mix at the end of specific rounds. When the targets (countries and / or bases) and the attackers have been determined, the players need to decide how they will meet the current alien threat. They now have to deploy their fighter jets to attack the approaching UFOs, but they also have to check whether they have build enough radar relays in their bases to track and attack even the far-flying UFOs. Otherwise the choice of UFOs which can be attacked will be limited. The ensuing battles then will be resolved by dice rolling, with the result of each battle being modified by the size of the UFO, the number of attacking fighter jets and the current aircraft research level of the alliance.

Chances are high that the players will not be able to deal with all approaching UFOs so that some of the UFOs will be able to deploy their ground forces. Now the players once again have to chose where to send their ground troops, and here they can split their troops between countries currently under attack and countries which are already cooperating with the aliens. For the transport of troops the players need shuttles which also are stationed at the player bases, and when all troops have arrived at the battle sites the players once again take out the dice to fight all individual combats. As mentioned earlier, in case of any alien victory the aliens will try to force the target country into cooperation so that alliance countries may become neutral and neutral countries may switch to the alien side. An alliance victory in an alien-siding country will make the country revert to neutral status, and an alliance victory in a neutral country will lead to a free diplomatic attempt for the alliance to sway the opinion of the target country to pledge allegiance with the alliance. And not to forget: the alliance will receive one point of alien knowledge for each ground victory, and these points are desperately needed for research!

Each round ends with some cleanup efforts, and so the players have to return all their units back home to their bases. However, if the base actually was attacked by an UFO which could not be defeated, some of the buildings at the base might have been destroyed. In this case some of the homecoming units may not find a matching hangar / garage / barracks, and in this case all units without matching building must be scrapped. In addition, the players now check whether they have enough alien knowledge and remaining laboratories to finish their researched begun earlier during the same round, and only if all requirements are met the new technology level is finished. Otherwise, all the money invested into research this turn will be lost! Finally, the container with the target markers needs to be updated to match the results of the current round, so that target markers of countries which have fallen to the aliens will be removed, whereas freshly freed countries will be added to the container.

There is a chance for an instant victory if either the alliance or the aliens have acquired more than 50 victory points, but the game finds it regular end after the 7th round. Now the alliance needs to possess more victory points than the aliens, but in addition the alliance also needs to have mastered the fourth level in their research of alien technology, the fourth technology which can be researched by the players apart from the three military technologies. Only if these two requirements are met the alliance can claim victory, so that all other constellations will lead to an alien victory.

This short description of Target Earth - Objetivo la Tierra might sound more complicated than needed, but I wanted to make sure that the general feeling of the game comes over with some details. However, at this point I should add that the game includes a few other things which offer even more finetuning. On the one hand all players will get a constant supply of alliance cards, and each player is allowed to use of on his cards each round. These action cards can be used for a number of purposes like the upgrading of an unit to "elite" status, improving research results, diplomatic attempts or even the gathering of additional alien knowledge. All these cards are helpful in the one or other way, any they are needed to counterbalance the otherwise frightening alien forces. However, there also exist some advanced rules which add real competition to the game, since now each player receives a hidden agenda card which will list an aim which the player needs to pursue in order to win the game. Thus, the players record individual scores of victory points in the advanced game, and these points will be awarded for their individual performance in combat and for other actions. Furthermore, each player receives his own unique faction, and the four available factions are the airforce, the army, the intelligence and the diplomatic corps. Each of these factions has its own strength and unique ways to score additional victory points, and so the advanced game puts up a challenge which is rather different from the basic game. Whereas the players in the basic game all need to follow the common goal, the advanced game requires the players to act selfishly and thus endanger the whole mission of defending Earth. The players are required to keep a good balance between contributing to the common goal and following their own aims, and so their whole playing style becomes quite more individualistic.

Whereas the rules of GEN-X GAMES last year's hit Luna llena - Full Moon sometimes were a matter of debate and disputed amongst gamers, I scanned through the rulebook of Target Earth - Objetivo la Tierra while I was preparing for the SPIEL, and these rules seemed to be much more straightforward. In addition, as this review should have shown, Servando Carballar of GEN-X once again has succeeded in finding a game with a somewhat uncommon topic which has a good potential to fascinate players for quite long playing hours. While the basic rules offer team-orientated interaction, the advanced rules may be used for competitive play and so the whole setting of the game changes dramatically. As a matter of fact the rules are not changed on many points, but author Jacobo Cagigal did well to include both variants since the game now can be experienced from two rather different perspectives.

Another point worth mentioning is the nice interaction between the buildings in the individual player bases and each player's military options. It seems well-matched to put up a correlation between the buildings and the different military units, since the players need logistics to keep the fight going, and it also becomes rather crucial to defend a base against an alien attack since the destruction of buildings might lead to the abandoning of troops. In a way, this reminds a bit of classic PC-games like Dune 2 or Warcraft (the old first edition) where the players first had to build up some infrastructure before they could start a military campaign, and here the author has elegantly integrated these logistical efforts into a quite new scenario. And, of course, there are also major similarities with the UFO: Enemy unknown bestselling PC game from 1994. It seems that Jacobo Cagigal must have known this game, since there are many elements in Target Earth which were present in the old PC game as well.