Most of the requirements are in requirements.txt so you can create a virtualenv with:

virtualenv --system-site-packages instapy.site.env
source instapy.site.env/bin/activate
pip install -r requirements.txt

Note that you need to enable system-site-packages because the project also requires pygame which does not currently compile using pip so you will need to acquire it by other means.

Once you have the requirements installed (and ensuring you have the virtualenv enabled -- the source ... line in the above script does this) you can run python run.py examples/objects/interactive.Game to try out the interactive example. You will also need to run python run_gui.py to initiate automatic updating (the main process just exposes a server). With these running, open examples/objects/interactive.py and try changing things (note that the init_once method is explicitly unmodifiable, so don't worry if you make changes in that and it doesn't work).

Bigass caveat: Behaviour on threads is undefined and will definitely do wrong things. Don't use this on threads.