Since you indicated an interested in ultimately moving the data to a separate file, I suggest YAML::Tiny

Using YAML::Tiny your data file would look like:

room: >
some text here, probably something
a few lines long

wall: |
    another text, here, this time
    pre-formatted (but must be indented)
[download]

But, I'm not sure it will handle multiple paragraphs. More likely the pre-formatted syntax would because it uses indentation.

That said, your parser for your syntax might just be the best choice for your application.