This series came out in two major chunks. The first releases were diecast-and-plastic versions of the standard Orguss and standard Nikick. Perhaps to simplify production, these pieces have only limited transformations: the Orguss can only switch from orgroid to tank mode, and the Nikick from humanoid to gerwalk mode.
The second set features all-plastic construction and full transformations. Both the standard and Olson Type Orguss pieces were issued in this series, and a version of the standard Orguss that featured a clear chest plate (revealing machinery beneath) was released as well.
These toys are very nice but have a tendency to break. Due to the design, they are often found broken even in their original boxes. Although their main components are diecast, all of the joints are plastic, allowing the arm and gun units to snap off very easily.
These toys are mostly plastic, but the feet are diecast. The legs tend to break at the waist due to the plastic joints used. Apart from that flaw, they are very nice toys.
This is the 1/60th scale version of the Terram Nikick. This is a very nicely made toy with diecast body and feet, and plastic for the rest of the toy. The toy transforms between humanoid and Gerwalk modes.