The General Course of the Wars - Spoilers Ahead

The Mutiny, 2028:

Dissatisfied with Grima's (NOTE: actual Goner names are painful to pronounce for humans, names used are the approximations that humans end up using for alien names) failure not to get more than half of the colonists and soldiers killed and even more left injured, several tens of thousands of Goners, partially coordinated by Limbra and his agents, attempt to capture Grima in order to force him into a trial that would inevitably lead to his execution.

Limbra kills Grima and his other bodyguards right as security cameras cease function due to one of his agents, and then slaughters the mutineers as cameras power back on, making it appear as though he was the only survivor of an overwhelming attack by the mutineers and prompting figures that had been fine with standing by and allowing Grima to be executed to partake in slaughtering the mutineers, such as Kusa's Crusaders.

Grima is succeeded by his cousin once removed Grimok, who is notably weak to both suggestion and bullying.

Introductory Combat, 2028

During the crash-land and mutiny, the militaries of most human nations around the world encircled the area where the aliens had crash-landed and stationed naval bombardment ships nearby.

This included such titans as NATO, the EU combined military, Russia, China and India. Switzerland's were not among the literally hundreds of millions of soldiers present.

The aliens, seeking to quickly gain the upper hand, launched an attack that resulted in the vast majority of the soldiers present being killed. Those of the weapons along the hulls of the crashed alien ships were more than enough to obliterate the vast majority of aircraft and naval support.

An attempt at firing 3 nuclear missiles by China resulted in all 3 of them exploding in Indian airspace, which would've caused nuclear war between the two nations if those present in India's nuclear bases hadn't been informed of the alien invasion and not wanted to wipe out fellow humans right in the midst of an alien invasion.

During the time since crash-landing and this attack, alien linguists - with the help of captured human scouts and the internet - have figured out English and release the following message immediately after the attack:

"Want Africa. Africa enough. No more fighting not Africa. Outside Africa can fight us if want. Will die. Accept surrenders."

This resulted in almost every non-African country pulling out what remained of their forces.

INSERT AFRICA HAVING A BAD TIME

South Africa capitulates in under a day. Losotho surrenders several hours later after Khanin, later nicknamed "Khan" for his name and the nature of his tactics (raze a few minor settlements without even asking for them to surrender, then ask for them to surrender, then take your entire army in circles around the country that get slower each time destroying everything in your path until they surrender) and a name that he would take great offence to after learning who Genghis Khan was due to perceived similarities to a certain individual in Goner history, did a thing. Khanin is promoted.

Namibia, Botswana, Zimbabwe, Mozambique and Eswatini, having no time to build any kind of defence after their forces were wiped out in South Africa, all surrender. Many of the wealthy and politicians flee to nearby islands and seek asylum in other countries but are given to the aliens when they release a statement asking for them.

Grimok orders for a temporary switch from expansionism to holding a defensive line and keeping down uprisings so that more than three quarters of the soldiers can be pulled back and used as workers due to the shortages the colonists are facing and the fact that their crashed ships have essentially turned into slums. Plus he's noticed how destructive the soldiers are, often indiscriminately killing civilians and soldiers, and wants to give more countries a chance to surrender rather than salt his own fields so to speak. Most of all he just wants some actual order within the seized territory as parts of seized countries have collapsed into anarchy, amidst which enemy forces that can sabotage the Goners can easily hide and wait for perfect moments to strike, and he wants the seizing of new territory itself to be more orderly, controlled and less destructive.

Angola offers a conditional surrender and, after being talked down on many of those conditions, becomes a vassal of the Goner Earth Colony. What remains of its economy is thrown into turmoil by the conditions, and the terms that Grimok publicises, notably not chosen by him but being policy of the Goner Empire, greatly discourage any other African countries from surrendering because the terms are just that "fuck you and put up with our ridiculous bullshit" like every third, sixth etc child being sent to the Goners to be a slave of their government (usually then sold at below-value prices to corporations owned by relatives of those in government positions, but also used as lab-rats and for special military/police work such as to infiltrate certain groups), complete demilitarisation (including of police forces, who are supposed to be replaced by ones sent by the Goner Empire... they tend to overlook and overreact to a lot of stuff), complete de-armament (including of the populace), making all records open to Goner Empire officials and letting Goners enjoy a set of rights more extensive than that which they have in their own Empire's borders including the right not to be taxed. They also take the families of all Angolan government officials, with exception to those who flee abroad with said families, hostage.

Almost all of what remains of Africa's nations unite their militaries under the ALA, which accepts volunteer forces from abroad. Lots of these volunteers are strangely well-trained, well-equipped and especially interested in collecting alien technology and mailing it home ("uh yeah uhhh my daughter wants an alien plasma gun totally not sending it back so scientists can wrack their brains trying to reverse engineer it"). Also a lot of religious people because...

It's confirmed by Grimok that the Catholic Church or more specifically the Vatican would be illegal under the Goner Empire as it bans theocratic states of religions other than the one the state endorses. The Italian government, prompted by the EU, offers to integrate the Vatican into itself with the condition of being allowed to investigate everything, which would mean being able to charge those in the Church with anything banned in the EU or Italy. The Pope dies of a heart attack. The new Pope declines Italy's offer and instead declares a crusade on the Goners, claiming that anyone who fights against the pagan alien invaders even non-Christians get a free pass into heaven. Just to clarify since Grimok did say "we only want Africa"; the Goner Empire doesn't allow the existence of other theocratic states even if they otherwise have no gripes with them, so even any countries outside of Africa that are theocratic are on the Goner Empire's hitlist.

Leaders of other theocratic states hear this and all either declare similar proclamations to the Pope or take advantage of loopholes like that which was offered to the Vatican, either reforming so that they're no longer officially theocratic or letting themselves be sublimated into non-theocratic states. This includes states not recognised by the international community (mostly areas under the control of religious terrorist groups) but the Goner Empire isn't the international community and mostly just cares about who actually controls an area. Imagine going to fight aliens and hearing everyone in your transport talk about how they're killing in the name of their gods when you just don't think every third child should be made into the property of a government that uses them as lab-rats and corrupt auctions.