There are 5 challenges about encoding/hashing algorithms, steganography, reversing, and more. Starting from easy to hard, the goal is to find the right answers and beat the challenge. Paying attention to small details and connecting the dots is the key to success.
Note: You shouldn't need port, directory, or file scan tools (nmap, Gobuster, dirbuster, ffuf, nikto etc.) and online brute-forcing tools (Hydra etc. do not use them to find answers on the site, you don't need them. However you might need to use john or hashcat on your computer or seek some solutions online). You shouldn't need to inject anything (SQL Injection, Template injection etc.). Do not use the tools mentioned earlier. These challenges are mostly for beginners, experts might be bored with this stuff as it might be too easy or obvious for them.
Last but not least, please do not share answers to the challenges online!