Currently there's a special promotion on the Steam version of HM2. If you buy HM2 on Steam, some of the money will go to Overkill (the devs behind Payday 2) and I don't want to support Overkill.
If I buy HM2 on GOG will Dennaton receive all the money or will some of it still go Overkill?

I assume Overkill get money because of the Pay Day 2 tie in. But there's no Pay Day 2 stuff in the Gog version, as far as I know. So I assume they wouldn't get any, they didn't have any hand in making the game.

Also, why don't you want to give money to Overkill, aside from the fact they didn't make Hotline Miami?

I just don't want to support DLC whoring companies. I mean for godsakes the game now has over 100 dollars worth of DLC on top of costing 30 bucks.

Edit: Their website only mentions the steam version but I'm still not sure.
http://www.overkillsoftware.com/hotline-miami-2-payday-2-collaboration/

I understand that you don't want to give money to certain companies. I also have some candidates on "my list".

But even if you for that reason don't buy the game, you would support the developers of HM. And no support for GOG if you buy it on steam.

Long story short: don't think about supporting overkill, think about supporting HM Devs and GOG.

After a bit of googling this issue, I think it's safe to say that when you buy the GOG version of Hotline Miami 2, no money whatsoever will go to Overkill, as it doesn't have the PayDay tie-ins that the Steam version has. Dennaton Games and Devolver Digital are the ones responsible for the game, and Overkill doesn't even have a distribution deal with GOG to begin with, so I really think there's no way you're giving Overkill any money when you buy Hotline Miami 2 here.

I couldn't find any word of an agreement between Overkill and Devolver or Dennaton, outside the Steam thing they have going, as well. There's always that possibility, but I highly doubt Overkill would get any money from a version of the game that doesn't have any connection with their PayDay franchise.

Also, Dennaton and Devolver are way smaller than Overkill, and I don't think it's likely they share sales revenue with Overkill, a bigger studio, if Overkill has nothing to do with the game.