I managed to soft lock the game by clicking the mouse after you hand in the tablets to the potted leaf. (Chapter 3 spoilers)
I played the game with a controller. Clicking on the screen when the first dialogue option appeared made all options unselected. I was not able to reselect them with any random thing I tried. I was able to pause the game, so I saved and then reloaded that save in hopes that it would let me progress the story. Instead the cutscene was exactly as I left it, except that I can no longer interact with the person who appeared from the potted leaf.
I do not know where this game saves it's save files. if possible, I'm willing to send them to you so that you can better explore this issue.
Thanks for letting us know about this. I have fixed the issue with clicking on the screen deselecting dialog options and that will be up in the next build. We will be taking out the ability to save and load during dialog or cutscenes. It is something that can break the sequence of events in the game.