On occasion, they're listed on the product page. Possibly with some of the info in tags as well.
On other occasions... they aren't.
And if it's a web game.... while it's not guaranteed, chances are it will probably run.
Honestly, I'd ask the developer first about it on such a subject and such a scenario, and listen to them. For example, if they say "You can give the copy to a few people at _____.", then I don't see the problem with it.
Otherwise, I wouldn't really re-upload it, in my opinion, as the developers probably have their reasons for taking it down (even if they're personal ones).
I understand alternative views. Some see a game as a work of art, and think art must be preserved. But, I think the comparison can still get a little muddy past surface level, so I'd still ask the developer.
Another thing I "might" have picked up on, but I'm really still thinking about...
While there may be Visual Novels that read like an actual novel........ as I play more Visual Novel games, I spot a slight difference between the two sometimes. The Visual Novel games I play, often focus on characterization and getting the personality to the characters correct, even at the expense of tight grammatical correctness in script. This makes me think that the writing to my own Visual Novels is too "tight", as it focuses too much on grammatical correctness, without the normal and "messy" short chatterings of characters.
I'll think about this some more, but if I need to change some things, it really isn't that hard of a change. So I'll think about it.
I just posted a thread where I covered a couple of subjects, including slowing down. Here it is if you're interested:
Things you've learned / picked up in the last week - General Discussion - itch.io
So my advice is to slow down, and that slowing down for just a bit isn't always a bad thing.
But, you could maybe also sometimes think about ideas for the game when slowing down? If you want to.
What are some things you've learned about game development, programming, art, music, sound, time management, writing, or personal goals in the last week?
I'll list mine:
I learned that my way of looking at things can be a bit rigid, and I'm working on that now. For example, I don't have to see art as "good" or "bad", there are many cases where two forms of art have quality or merit, but portray different styles or vibes. And there is also art which doesn't really seem like art form, but even it can portray a particular style sometimes and in some cases.
So, I think I need to "slow down", even if game development is a type of thing which encourages time-crunches sometimes. For example, I'm getting progress done at a pretty steady rate on my newest project, but I think it would benefit the game for me to take 2-3 days off from actual development to weigh the direction of it going forward and plan from there. Especially with a game like this with a pretty strong visual focus.
I wish I had some big inspirational story to tell about how I decided. But it wasn't until I released my first game demo and saw some feedback, that things took on a life of their own, and I felt more inspired to make games. Before that, I saw making games as a type of cold, hard programming project with moderate to strong visual focus.