For images, optimize them so they don't take too long to load.
Option 2: Serve each label or part of your game via requests to a server. This is... well, people will still be able to see it on every request, but at least it will take them more time and sadly means a lot of work for you.
Option 3: Don't put your game online, create a Native App.
Sadly, there's no way to protect your images on the web... at least not an easy one, therefore if you really need them to be protected, then you'll have to create a native application but don't worry, that's not too hard!