The first thing I did when I opened the game was click the credits button. At first I thought you forgot to implement the credits screen and accidentally mapped the credits to the "start" button. I thought I was watching an intro cutscene, but no, apparently this game is just so dang polished that this is the actual credits screen.
The game itself is also very good. It was a bit difficult at first to memorize the recipes, which made the first couple of attempts a bit frustrating, but once I memorized the steps it made a lot more sense. It definitely got a lot more fun once you had multiple furnaces, forcing you to prioritize and schedule your activities.
Overall very good!