At the bottom of this file you will find a payload -- a blob of data that has been obfuscated in some way. When it is decoded correctly, the payload will turn into another text file with another puzzle. There are many puzzles wrapped inside each other, like a matryoshka doll, or the layers of an onion.
You will need to write code to do the decoding. This can be done using any programming language.
Every layer clearly explains how to decode its payload. These are puzzles with deterministic solutions, like Sudoku, not riddles. I'm a software developer, not the sphinx of Thebes.
There is a little bit of educational value in each layer. In order to progress, you will need to learn and use computery concepts like bitwise operations, encodings, cryptography, error detection, and so on.
Here's a fun project attempting to explain what exactly is happening under the hood for some counter-intuitive snippets and lesser-known features in Python.
While some of the examples you see below may not be WTFs in the truest sense, but they'll reveal some of the interesting parts of Python that you might be unaware of. I find it a nice way to learn the internals of a programming language, and I believe that you'll find it interesting too!
How to solve the 3x3 Rubik's Cube. Go back a couple of pages and you'll find the algorithms for the other variants.
Somebody's writing a clean-room implementation of Solomon's Key for the NES. All of the original levels are already implemented. Theoretically cross-platform. Doesn't quite work yet but it's getting there. Includes a level editor so you can build your own levels. Seems to have some tricks to getting it to run but I haven't tried them yet.
System Syzygy is a story and a puzzle game, in the style of Cliff Johnson's classic Macintosh games The Fool's Errand and 3 in Three, and of Andrew Plotkin's System's Twilight. As you move through the game, solving a variety of different kinds of puzzles, the game tells the story a piece at a time. By the end of the game, all the different puzzles and pieces of the story come together into a single meta-puzzle.