It sounds like your internet connection might just be failing during the download? It's 351 MB so a relatively large file. Sorry, there's nothing I can do to help with that.
You shouldn't need the full Microsoft Visual C++, just the Visual C++ Redistributable that I link right above the download, in the install instructions ...
( fwiw I don't think the object replacement rules are consistent between the web player and the downloadable client? in terms of what ends up on top ... )
Make to unzip the whole zip file, and run tree.exe from the same folder as all the dlls! (It won't work if you try to run tree.exe directly out of the zip file; you need to unzip the whole folder first.)
It tries to disable vsync and framerate limiting, so the game will run as fast as your computer can run it. So, if you have a slower computer, it does nothing. If you have a fast future fancy computer, everything may run comically fast while 'p' is held ...
oops, thanks for the heads up; I didn't think about that! I did buy them, and I'm not sure how else to distribute them, but I've updated the zip files to remove all the ones I was not using and added a text file pointing people to the purchase link ... hopefully that helps ...
I'm not planning to make any additional versions but if you'd like to explore the levels beyond that, there is an "unlock all levels" option in the options menu.
