After you've downloaded a game, you should be given the option to update the game if new files become available. This is going to be tricky because itch.io currently doesn't have versioning for files uploaded. But, it could be as simple as just looking to see if there are uploads with ID's greater than what was there at the time of the download for the given platform.
When a game is updatable the UI should show it, and it should give you an option to update. The same logic for game downloading can be done to find the file to download (but it can exclude files that have already been downloaded) #4
After you've downloaded a game, you should be given the option to update the game if new files become available. This is going to be tricky because itch.io currently doesn't have versioning for files uploaded. But, it could be as simple as just looking to see if there are uploads with ID's greater than what was there at the time of the download for the given platform.
When a game is updatable the UI should show it, and it should give you an option to update. The same logic for game downloading can be done to find the file to download (but it can exclude files that have already been downloaded) #4