I'm starting to notice if I search for something playable in the web browser, trying to discover a new game, that I'll often get something that's 5 minutes long followed by "Get the rest of the game / an expanded version of this game / the sequel / the downloadable version", often followed by, "...on my patreon / steam / personal web store." Either that or I'll hit an invisible wall that says, "This area not available in demo/web version".
It wouldn't be so bad if a loud and clear "DEMO" label were placed on these kinds of games, especially if they used to be complete games, but then were expanded off site with the existing content now having invisible walls / paywalls leading off to the new content.
It also seems kinda scummy that they'd put something up expressly to move activity/payment away from itch-io. I've been advocating for people to sell their games on itch-io, but not by redirecting people away from it.