You might like nandgame.com. It's the same ideas but in a visual drag-and-drop format, which can make it a little easier to get your head around some of the ide

You might like nandgame.com. It's the same ideas but in a visual drag-and-drop format, which can make it a little easier to get your head around some of the ideas. I found it helpful to work through all the exercises there and then go back to the Nand2Tetris course.