The difficulty of this puzzle cube does not come from the amount of pieces, and thus is not as tedious as a 10x10x10 or even a 20x20x20. In fact this puzzle cube only has 10 different pieces. The pieces fit together snugly, and when fully assembled the cube holds together almost on it's own. This happens because the pieces lock together and prevent eachother from sliding out.
I designed this cube in Blender, and then recreated it in Fusion 360. In Blender it is easier to create complicated shapes than in Fusion, in my opinion. In Fusion 360 however it is way easier to create stuff in proper scale, and accurately.
You have to put the pieces together in the right order, or they will prevent eachother from fitting. The files are numbered in the correct order, so you could rename them before printing to change the order and prevent spoilers. Don't hesitate to look up the correct order though, since the cube will still be very hard even then. I would even say that, unless you are very good at puzzles, looking up the correct order turns the cube from impossible to hard.
The color pattern I used is achieved by printing pieces 2, 4, 6 and 9 in a different color.
I made a quick solving animation in Blender. You can use this as a solution.https://youtu.be/8K9YEUObldA