I've zipped up the portable image with a Windows interpreter. Drop the image on the exe to get Squeak running. Or drop the portable image on the Squeak platform of your choosing. zip 
Check the archives for an interpreter for your Mac or Unix or whatever. I've also zipped up the source and a couple of patches I needed for version 1.20. You will want to get a full Squeak environment (with source and change files) before you try to look at these. zip
Hans-Martin Mosner has converted Plumbin' to use Squeak's new Morphic graphics model. File-in this change set after you have tried the MVC version. file
Try adding a new kind of tile to Plumbin' yourself. Make a subclass of Tile and TileView or TileController too, if you need them. Put it in a category with your name on it, something like Plumbin-PressureTank, and email me the fileout. I'll add it to the add-on repository.