Just want to make sure but if I buy a game, I can still download it at later date even if the dev of said game deleted it in the future right? Like, I bought game ZZZ in this month, can I still download it in December if the dev decided to remove it in October? Also, what about those free games? If a user already included a free game into their library, what will happen to it if the dev decided to remove it from the platform?

We protect buyers in a different way. :) If a game has been bought at least once, creators are strongly discouraged from deleting it. They'd have to contact support and provide a good reason. (They can of course hide the game and stop selling it, then existing buyers retain access.) For free games there's no such protection, so if creators decide to pull their free games, they're gone. You should probably keep copies of those with priority. Hope this helps!

From what I remember, if a dev decides to remove a game from the website, it will not be available for download. Devs are discouraged from doing that, but at the end of the day, it’s their decision to make.

I would suggest to download a game as soon as you buy it, and keep a local copy of it. This will guarantee that you will have access to it forever.

Hope that helps :)

Edit: Beaten by 7 seconds, will keep this comment up for completeness.