Solution

There was a secret message hidden in the audio file. The picture was placed here to help you find the decoding method. The Cube and the writing on the wall hinted at the game called Portal. Adding the ham and the radio and as a result googling for "portal ham radio secret message" revealed the method which the Portal developers used to hide easter eggs in their game. The audio file then could be decoded using any SSTV decoding software (MMSSTV, for example), which revealed an image with a giveaway code. The giveaway was for a collection of the MYST games.

Original post

Do you like mysteries? Do you like solving puzzles? Do you want a piece of cake? Have at thee!

Mysterious

Level 0, ends on Feb. 22 (somewhere around midnight GMT).

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