The 4D platonic solids are very similar to the 3D platonic solids in many ways like properties and shape, but, the biggest similarity is that you can clearly see how each 4D platonic solid is similar to its 3D counterpart.

You may be wondering which of these 4D shapes can fill 4D space, considering that only the cube can fill 3D space on its own. And the answer to that question is that the tesseract, 16-cell, and 24-cell can all fill 4D space. (In 2D, this is called a tiling, and in 3D and 4D, it is called a honeycomb.)