@ Asriel Dreemurr Tiniest Goat
Okay, here's the gist of what happened.
It more or less started out with Zoe Quinn's ex releasing a tell-all about her, claiming that she slept around with at least 5 different "journalists" in exchange for favor for her "game," "Depression Quest." She may or may not have admitted to doing so (I never got that straight myself), but given that "Depression Quest" is utter garbage (it's more like a "choose-you-own-adventure book" but it's not good enough to be even that), corruption is the only way that it could possibly have gotten anywhere.
That was starting to die down, but then over a dozen different gamer news sites published articles declaring that "GAMERS ARE DEAD" within two short hours. They actively condemned and ridiculed their entire customer base, and the game devs themselves.
That's about when Sarkeezian started her crusade, along with the SJW cult. They whipped everything into a frenzy, stating that gamers are all straight, white male misogynists, liken to terrorists, but yet at the same time worthless and fragile. A push to literally make games not fun had also been under way.
In the middle of all this, "#GamerGate" was created. People had enough of the hyper invasive PC culture, and were sick of being demonized by a bunch of whining hipsters. They pushed back, demanding ethical practices in journalism, and produced genuine and credible studies, and facts. They dug into the pasts of the game journalists and the more outspoken SJWs, revealing them to be morally bankrupt frauds and hypocrites (and in some cases, substance abusers). Including Zoe Quinn, who among many, many other things, had committed charity fraud multiple times.
Further digging found that the SJW/PC invasion was at least partially organized. A conspiracy was underway to create a culture war and overtake the gaming industry. (See MexPirateRed's video above.) There is even some evidence that greater powers (IE politicians and lobbyists) had funded certain game journos to push this ideology, in an effort to destroy the current culture for them to swoop in and save the day with gamified "Common Core" programs.
As things went on, Anti-GG's antics continued to escalate. They started harassment and doxxing campaigns on numerous people. They called in bomb threats on at least two different GG meetups. They've cost people's jobs and business. They've pushed their agendas into schools, including grade schools. They've shamelessly used the deaths of people and other tragedies to bait emotion and further their agenda. All while making every effort to silence and deflect any and all opposition they face.
BUT despite it all, GG has been winning. The SJWs, feminists and hipsters believed their own lies, and expected gamers to just roll over and let themselves be destroyed. But we fought back. Gamers are not all lazy white men. Gamers are naturally diverse in just about every way possible, and are some of the nicest, most patient, driven, and high achieving people there are. Our very existence debunks their narratives.
They believed themselves to be infallible, so when their feckless ideals and narratives were challenged and then effortlessly destroyed by the very people they've been taught to hate, they did the only thing they knew to do. They threw a pansy fit. And in doing so, they exposed themselves as the hypocritical, pseudo-intellectual monsters they are.
Everything sort of came to a head when Anita Sarkeezian and Zoe Quinn were allowed to speak at a UN assembly. They drug up fraudulent studies from the late 90's-early 2000's about games turning people into sexist or violent monsters, that have been debunked dozens of times over. The two wanted to impose mass censorship on the internet itself, that would, among many other things, make it a crime to disagree with any woman about anything, ever.
The only thing they really achieved was destroying both the UN's and feminism's already inexcusably poor reputations. The UN's official report of the meeting was so laughably terrible, full of errors that you wouldn't even see in a middle school research paper, that they deleted it from their own official website.
The events of GG have slowed down quite a bit, but is still going strong. Until ethical practices are unilaterally enforced on game journalism (and other journalism), and the influence of SJWs', feminists', hipsters, or anyone like them, on society is completely removed, GamerGate and movements like it are here to stay.
[For more information, comb through the GamerGate image gallery. Almost the entire history of it is documented there.]