Do I have to go into each individual game sheet page and add to cart ? I didn't find an easy way to select multiple games from the search page.
I'm curious what the total sum of GOG games currently is.
If the total is not insane I might consider doing that as a 'thank you' to GOG as a DRM free platform.

Oh, I see. It's easier to just buy the whole wagon than pick out the interesting pieces. I'm totally with you. I need a way to compulsively buy a game before logic, reason and that part of the brain dedicated with up to date bank account status kicks in. Those few seconds that I use up to select a game and then add it to the cart is just enough to get these parameters into action. I think a Buy It Now! button directly connected to my Visa will be a sufficient circumvention.

Unless I miscounted:
140 games (or packages) at $5.99 = $838.60
94 games (or packages) at $9.99 = $939.06
Whole current GOG catalogue (234 items) would be $1777.66
If you have that much money around I'd rather you'd support some charity with $1500 and use the remaining $277.66 to buy games you actually enjoy :). You'd still send a clear message. Or rather two messages.

I think the promo bundles do this, but other than adding stuff to cart, I've never seen any way. Last time this came up someone mentioned a price in USD of 1300 and change. I would think with the new game additions you could be looking at around 1500-1600 USD.
If that's too rich you can buy the promo each and every Friday, that gets you a price between 30% and 50% off. You'll also be adding 2-10 games a week (more than most folks could reasonably get through in that time).
If you want an easy way to do this via the UI I'd just open a new tab per game off the long list of games and go through each tab pressing the Add to Cart button (or whatever it's called) were I you. I believe this would work and not be too onerous.

Agreed. I'd also throw in some money for indie developers too.
Supporting GOG is a nice thing to do. But to do it so comprehensively means a lot of your money just goes to companies like Activision, Ubisoft and Strategy First. Which isn't quite the right kind of corporate attitude to support.

By throwing money Activision, Ubisoft, and Strategy1st's way you're helping GOG by saying, look, GOG makes us money, so we might as well release all of our old games that way.
Plus, DRM free games is something to be encouraged. A boycott of everything a company produces is crude, but a boycott of their most egregious offensives and an anti-boycott of their DRM-free, reasonably priced and featured games, will actually contribute more to them changing their ways.

You're right, when they look at the balance sheets they need to see that DRM free sales make a significant portion of their back catalog sales, otherwise, to them, what is the point?
As for the charity thing, I won't presume to tell anyone what to do with their money. For all we know this guy earns 200,000 USD and already donates more than some folks earn yearly to charity. And even if he doesn't, it does not matter.

If Strategy First didn't declare bankruptcy whenever a developer asked about what happened to their pay check then I might still be naive enough to consider them redeemable. Many publishers need major changes, but no other needs to be utterly destroyed like this one.
Activision make too much money treating their customers like retards to pay too much attention to some small minority looking to make intelligent, informed purchasing decisions.
As for Ubisoft, they're bipolar. They swung from outright DRM-free to major DRM overkill in an instant. Now they're swinging back. But like Microsoft, you can't really trust whatever stance they adopt towards the PC to be a lasting one.

There should be a big 'buy everything!' button on the front page.
PS. You'll save a ton of money through promos. I'm sure GOG wouldn't hold it against you, though that's very generous.

Keep the money for the next "Humble Indie Bundle" and we'll see if you can top Akwater's highscore :D
I myself would not be spending money on games I'm never going to play anyway, and if you like to collect games it would be way cooler to have something physical instead.
In the past I've had that bad habit of grabbing gems on sales I've absolutely no interest in. Be it for 1€ or 1 penny, I'm not getting a title that doesn't interest me.
Just my 2 cents.

Add one game to your cart, the you will have at the bottom of the screen the "Recommended for you" section, from there you can drag and drop the game icon to your cart, they will be automatically added.
Once you have added all the game from the "Recommended for you", go back to the catalog, select another game and do the same.
It's not perfect but it will be much faster than selecting all the games one by one.
239 Games if you count the removed games and the free ones (I counted twice).

Granted. Sorry if that came across presumptuous.

They will owe you forever for those 88 cents :)
Is any other game download service offering such an option (the buy all button)? I don't know, taking into account the lowest common denominator of potential customers one might actually "accidentally" click on the button and purchase it all in one go...
...in retrospect that would be pretty stupid (superior being help him/her!) and they don't deserve to own that money anyway :P

Even if the 2nd Birthday promo isn't that huge, the Christmas one should be very comprehensive if last year is anything to go by.