Placing the gears externally, so that their orientation can be seen, Adding gear teeth to the corner and edge pieces and using a new speed cube inner core.
These steps result in a twisty puzzle that on the one hand has some of the features and attractiveness of the original Rubik’s Cube. Whereas on the other hand it creates a completely new and unexpected solving experience.
To summarize, the following aspects add to the attraction of Gear-Cube;
A first solving reward is getting the puzzle to its cubic state. This is relatively easy.
A second solving reward is getting the puzzle to a state where each face has only two colors (of opposite faces).This is a bit harder, but achievable for many people.
Hardest is solving the puzzle as a whole, which is still easier than the original Rubik's Cube.