it is possible some of your browser extensions are doing "funny things" and making you unable to download it.
like it happened to me just now (specifically a "pop-up blocker" one). Try disabling it for itch.io pages specifically - hopefully it works out for you like that.
yes, the game is still available to download, and looking at the game's analytics, there have been people who have successfully downloaded the game recently.
I'm not sure why the install isn't working for you. Maybe trying it on another browser or service would work.
I'm using Itch's client.