Nope. that's not how it works. Only new installs after the threshold count.
From their FAQ: "We are not going to count web and streaming games toward your install count." Demos will be viable. However, they want to block the loophole of avoiding the fee by distributing a demo that you can upgrade to a full version. A game with in-app purchases for unlocking more content is not a "demo." Free games won't be impacted because of the revenue threshold. Unlikely. It is legally very shaky to pull once-sold products from players' accounts and involves more than just the publisher. You forget the revenue threshold. If the game is not seeing many sales, it won't hit the threshold and there will be no charge.

but frome their Q&A:
"Q: Does this affect WebGL and streamed games:
A: Games on all platforms are eligible for a fee but will only incure costs if both the install and the revenue thresholds are crossed. Installs - which involves initializations of the runtime on a client device - are counted on all pltforms the same way (WebGL and streaming included)"

Not app purchase. More like the old shareware model like the good old Doom. Many games today, especially indies, still use the same model. So you download the game, it gives you the first level or hour for free, then you buy the the game which gives you a key to unlick the full game. This model no longer works.

It isa little shaky, but legally they can. This is all i the licensing agreement. In anyway, if they cannot then for the delopers this is even worse, as they cannot protect themselves and then being hit with a fee from Unity that they have no controll over.

There is also a subpoint 5b here. Review bombbing is bad, but with this a few people can bancrupt a developer by buying the game onse (on a sale for example) and then just install it over ad over on several devices.

{quote]
No, this is the for the old an successful games, the threshold is passed. They do not need to hit the threashold again.

That's probably outdated. Not a big deal. That model was useful back in the 90s when distributing games was much harder, it doesn't matter so much today. You just download the full version after the purchase. It has to be in the end-user facing terms on the store that the game was bought on. Have you checked what the terms e.g. on GOG say?

It also has to be compatible with local consumer protection laws, etcetra. A developer unilaterally pulling a game from an end user's account is legally MUCH more complicated (and risky) than just stopping new sales or paying the license fee. They can stop selling or they can upgrade to a subscription where the thresholds are much higher (and fees lower). That assumes there is no way to detect install bombing. I'm pretty sure you can tell that something fishy is going on if a small indie game that only ever sold 200k copies is suddenly being installed millions of times. That threshold is revenue per last 12 months, so you need to hit the threshold with recent ongoing sales. If some old and successful indie game is still making $200k a year, they've clearly hit gold and either upgrading the license or just paying the 20 cents for new installs isn't going to bankrupt the developer (unless it's some freemium shit with millions of installs but a handful of paying users; I won't shed a tear for those).

I have plenty of Unity games that run silently. On the other hand, Valhalla Hills, made with Unreal, is something I've never been able to play because the fans go to max after a few minutes, regardless of settings, and never stop until the game is closed. And it should be a relatively low-end game.

That's...not how any of this works, at all, for any engine. There's no "internal Unity format" or anything. Textures can be compressed or uncompressed; if the devs are mostly using uncompressed textures and just leave it at that, then the game could potentially zip well. Uncompressed is fairly common for 2D games, however you can mitigate the file size by using an external format like PNG (not JPG, which has no transparency and therefore could not be used for sprites). GPUs do not use PNG, so PNG files must be loaded and then uncompressed, which adds some loading time. Possibly the devs didn't do that, either intentionally or not, which isn't Unity's fault.

When considering compressed textures, compression on GPUs is nothing like JPG, but rather a type of lossy compression that's always a fixed size. There are a number of different GPU compressed formats with different qualities, but e.g. DXT4 or DXT5 compress using a 4:1 ratio, so a 256x256 texture that's 2MB uncompressed will always be 512K compressed. (All this is ignoring mipmaps, which increase texture file sizes and memory usage.) It's quite possible to do much better with JPG, but again the textures would have to be stored externally as JPG files, loaded in, and then converted to a GPU compression type, which can significantly slow down texture loading, as well as possibly being lower quality than pre-compressed textures. Not to mention mipmaps would have to be auto-generated, which you might not want for various reasons. And this doesn't work with texture streaming. All engines have to deal with this sort of thing as it's inherent to how hardware works. It's not that common to find textures stored as JPG; mostly they're stored in a native GPU format for efficiency.

LOL, that was blindingly obvious from the beginning.

They absolutely legally can not, and it is not. No, because that requires a way to detect installs, which they don't have. Instead they have a "proprietary data model". Whatever that means. Could be a random number generator for all anyone knows.

Well, it's not like I couldn't. It's just that I found the process of making games began to destroy my ability to enjoy playing them. And since they had always been a major source of enjoyment for me I feared losing that. So I decided to do professional programming in other areas instead.

If the game is 100% free moneywise, with no means to generate revenue, then it can't hit the revenue cap.

(This means that something like Daggerfall Unity isn't affected by this change.)

But this won't prevent people who previously downloaded the installer from installing the game later.
I believe that the revenue threshold, unlike the install count threshold, only checks the last 12 months.

What I was thinking though is if they are not responsible for those potential charges if they back out of the license agreement and no longer distribute anything with the engine.

In other words if they no longer have an active license.

Is there a list of which games here on GOG use Unity? Perhaps I should download the installers now, and make a list so I can check if they connect onlne, and block them if they do.

I don't know of anything comprehensive. Off the top of my head I think Rayman Origins, Pathfinder, cuphead, Mimimi games (like Desperados III), and Solasta.

Meanwhile in Unreal Engine news:
https://www.youtube.com/watch?v=POwTaVZ_CA0

Yeah I thought that was a bit too much.

You've obviously never done programming before. When you write data from a program you make you have to decide on a format. Maybe you include a header, but as long as you can serialize and write your data out and get it again and use it, it works. Maybe it's a public open format like csv, or maybe it's something you decided on like 32bit size of block, 16 byte for the name and that's it. Repeat until run out of file. Either way, your program will be able to read the data and nothing else probably will (unless they go out of their way to implement it).

Thus Unity writes using it's own format for unity programs. Got it? Good.

They likely store blobs of data (textures, graphics, videos, animations, etc, if you use SQL databases you'd understand Blobs) that would probably be copied verbatim. But that's not what I'm talking about. I'm talking about absolutely huge files that compress to like 20Mb. Not textures, or data.

So trying to find a good example here i found The order of 12. 530Mb big, but i have it stored as 46Mb in a 7z file. Even recompressing as a zip (so each file has it's own compression ratio data unrelated to others, weaker compression but still relevant) you can see a huge amount of... likely empty unused space. Why can't that unused space just get removed to reduce the game to say 100Mb? I don't know.

Do you have a better source for that news? One that doesn't auto-play video, and preferably one that's text-focused rather than video-focused?

(I checked Unreal's FAQs, and their licensing is much more sensible than Unity's, though of course still nowhere near as good as Godot's.)

Gog is already having trouble getting some games, and even getting devs to keep them updated with content and bugfixes. This will make that worse for sure.
Rayman Origins uses an engine called UbiArt and not Unity as far I remember.

Why would it effect GOG any different than any other seller?

Oh, sorry. For some reason I had it in my head it was Unity.