Easy-to-assemble kits with a small number of pieces, typically designed for younger children or complete beginners. These kits usually involve building basic shapes or small, single-piece models.

Kits with a moderate number of pieces that require following more detailed instructions. These models might include simple mechanisms or slightly more intricate designs, suitable for builders with some experience.

Larger kits with numerous pieces and intricate designs. These models often feature more complex mechanisms, such as moving parts or detailed architectural elements, and are intended for advanced builders.

High-complexity kits that involve advanced building techniques, including the integration of gears, motors, and other technical components. These kits may require a deeper understanding of basic mechanics and engineering principles.

The most challenging and sophisticated kits available, often with a large number of pieces and highly detailed instructions. These models may include more advanced electronics, programmable components, and require a larger time investment to complete.