Assuming that we have a universe with four spatial dimensions plus time, within which atoms exist that can form solids, liquids, gases and plasmas, the compounds that can be formed having physical properties equivalent to those in our 3D universe, such as mass, friction, elasticity, hardness, strength and suchlike.
Within this universe, within a portion of it with solid, liquid and gaseous matter that has a 'down' direction with solid matter below, there exists terrestrial 4D sentient beings who have conceived a desire to modify their environment and to build tools and machines to make their lives easier.
What physical tools and machines are possible in 4D space?
Are there any machines that exist in 3D that are not possible in 4D, and are there any machines possible in 4D with functionality that cannot be duplicated or approximated in 3D? Examples addressing equivalents (or lack thereof) to common 3D machines would be appreciated.
Are there any online or offline resources that discuss and provide examples of mechanical systems in 4 spatial dimensions beyond the properties of simple 4D shapes?