Just finished it as well. Overall the art/sound/story/humor are all pretty good, but the gameplay and UI are absolutely terrible the entire way through. The general lack of polish also makes the game frustrating to play through. A lot of the things that even have names to click on have no description at all, and when they do it's the same generic message for all of them. Worst is when correct actions have no indication that they're a good idea until after you've already done it.
I would also remove all of the click-and-drag elements and replace with the traditional point-and-click style which is the namesake of this genre. It's not like point-and-click doesn't work on tablets, which feels like the root of these ugly UI decisions. It seems especially weird that the final puzzle has no click-and-drag at all, normally your gameplay elements teach the skills needed to complete the final task, at the very least these should be consistent.
I really hope they plan to polish some more once the save system is working. The recent kickstarter post seemed imply they were gonna kick it out the door as soon as it was functional, which would be a tragedy since the game underneath all the problems is actually decent.