I was wondering if theres a way to just update the game with the halloween update, or if you have to redownload the entire thing. It looks like you do?

Which game would that be? This is the wrong place to ask for help with specific games. And is this in the app, or directly? The app can auto-update games.

If you use our app then updates will automatically be installed (if the developer configured their files correctly). If you downloaded a game right from your browser then you will have re-download the game to get any updates generally. (Some games may provide their own built in patching infrastructure, but unless you see some kind of “updating” screen then it’s unlikely they’ve done that)