Hy, it's supposed to have:
- One executable (Pixelorama.x86_32 or Pixelorama.x86_64)
- One PCK file (Pixelorama.pck)
- A pixelorama_data folder (containing brushes, patterns, etc...)
For Linux Pixelorama comes in portable form.
There's also an official Flatpak available as well: