While they are designed to be modular, we purposely do not change themes often. That’s because the same adventure is never exactly the same twice.
Each adventure has multiple endings (based on performance) and varying content, such as randomly generated game sequences or changing solutions to a challenge. While an adventure may appear seamless, it is actually a living, responsive environment that will respond to your performance and change the difficulty and story accordingly.
There are also secret challenges and extra content hidden in each adventure that you are very unlikely to unlock on your first time through an adventure. You can find hints on how to unlock this content on any adventure’s page, but most of them are very difficult to figure out!