The file (I re-hosted the file on MediaFire) can either be obtain from the website
or from the game folder of pwnadventure2_Data.
The next paragraph explain the steps need to be taken if file is obtain from the website. Skip the next paragraph if its obtain from the game folder.
If the file is obtain from the website, the file extension will need to be identify. The file is identified to be an .xz file using TRid online. Opening the .xz file with 7zip, it contain another file without a file extension. After identifying the file, it is the same .ogg file that can be obtain from the game folder.
The .ogg audio file can be played and analyse using audacity. After listening to the audio file, I notice that there is a constant beeping sound in the music that have resemblance to the beeping of Morse code.
Waveform of a beep:
Waveform of a dash:
The first beep starts around 18.10s .
After listening to the entire audio file, the Morse code is obtained:
.- ... - .- .-. .. ... -... --- .- .-. -.
Converting the Morse code...
entering the key and 50 points =D