I think it would make the game much more interesting if tools and tiles interacted with each other in ways that encourage more creative solutions: For example, if water leaked into surrounding tiles, and the heater made water evaporate, with a little math you could set up a gradient of watering around a sprinkler letting you grow different plants with different water needs (as opposed to ignoring any plant that needs less than 100% water because they can't be automated, which is what I'm finding to be the best strategy at the moment)
Wow. This one's got potential to be one of the legendary ones, up there with Myst and the Submachine. The story and gorgeous art would be enough, but ya'll managed to nail the little technical details too. Anyone else making an adventure game: take notes, this is how you do it right. Take all the time you need to make the next one just as good, but know we're eager to play it when its ready!