"Is there somewhere a short summary about this GamerGate thing?"
I'll give you one right now:
1. Zoe Quinn, a female feminist indie games developers, makes a free game called Depression Quest.
2. Zoe Quinn has relations with some guys. One guy in particular, Nathan Grayson, works at Kotaku and worked, until recently, at Rock Paper Shotgun.
3. Zoe's ex-boyfriend leaks the story, but others tack on an argument that Grayson supposedly reviewed her game for RPS and/or Kotaku after relations occurred. This leads to a gigantic engine of anger about supposed "corruption" in gaming, even though this.. never happened. All over a free indie game about Depression that none of these people cared about to begin with.
4. Lots of drama occurred. Lots and lots of horrible things tossed at Zoe, Nathan, Kotaku, RPS, etc. etc. It's abundantly clear through all of this that it's really about anger directed at feminist critiques of gaming. Corruption is basically a red-herring. Slut-shaming is abundant through all of this (a common joke was to reference the "five guys" Zoe Quinn had sex with, and her ex-boyfriend was a central character to pushing this so-called controversy).
5. The controversy is dubbed GamerGate. Its proponents become a little bit better about hiding the anti-feminist roots here and try to make it actually about corruption. The problem is that the real corruption in gaming, AAA developers buying coverage, is basically the opposite of what these people are angry about. For them, corruption in gaming is really about attacking feminism. Anita Sarkeesian releases a new video. This whole thing ends up becoming about her, even though she had no part in even the non-corruption referenced above. Again, the campaign against "corruption" reveals itself.
6. Most people move on. Only a few rabble-rousers are out and about trying to whip things up. For the most part, this is a dead movement already, as they have no real goals or even real things to complain about. At the end of the day, their main objective is to get feminists to stop having opinions. Good luck with that!
There are other things people would bring up too: such and so Kotaku editor lived with a person whose indie games she covered. A bunch of websites wrote about the word "gamer" and what it means. Lots of GamerGaters took this as a war of identity, even though RPS has basically embraced the word gamer. There's also been a lot of doxxing and counter-doxxing, supposed fake-doxxing (though with no real evidence, lots of people claim that Zoe, Phil Fish, and others are leaking incredibly private details and photos to gain sympathy or something?), etc. etc. And I haven't touched upon all the controversy and mud-slinging over the Fine Young Capitalists gamejam.
A few interesting discussions have come out of all of this: about transparency, the ties between developers and so-called games journalists, etc. But most of this has been lost in a sea of anger and stupidity. I think games websites could be slightly more up-front about connections between staff and developers, but I don't think that's really what this is about for most of the people involved.
