I did both this and the Nand2Tetris course before realizing that they are implementing the same computer -- this is an interactive graphical version, while the original Nand2Tetris uses a textual HDL where you write down the connections between logic gates as text, instead of clicking and dragging to indicate them.
I found them both fun and educational, but I thought the NandGame was more fun. But it's good to know about the connections, for example because there are more follow-on exercises that you can do from Nand2Tetris (working with higher layers of computer software) after you complete the NandGame. Or you can just be aware that you can talk about the experience and the substance with people who have done the other version!
I tried nand2tetris and my hardware class was one I did best in in college. Yet I found this class and book to be very much "rest of the Fine owl" and I had to refer back to my college textbooks and even my tests to do the assignments. I gave up about halfway through as you had to complete more or less the main part of the CPU. I felt the lectures and text were lacking to say the least. Maybe in the age of the internet (I graduated a bit over 20 years ago) this is the norm these days but I expected the course and text to be more or less self contained.
I found them both fun and educational, but I thought the NandGame was more fun. But it's good to know about the connections, for example because there are more follow-on exercises that you can do from Nand2Tetris (working with higher layers of computer software) after you complete the NandGame. Or you can just be aware that you can talk about the experience and the substance with people who have done the other version!