The top-level files that you rUn in drracket or otherwise are:

* areas.rkt
* ridge.rkt
* summer.rkt
* winter.rkt
* door.rkt
* weave.rkt
* weave2.rkt
* glass.rkt

The other .rkt files are files they 'require'

Most of these generate .png files with the same names.
If you want to suppress this, replace the string containing file name in the call to 'environ' by #t.

This won't work for summer or winter.  For these, just remove the call to save-pict.