The aim is to solve a real-time packing problem by forming complete rows, which then disappear and score points. Poor play leads to incomplete rows, caused by inefficient arrangements of tiles; these rows do not disappear, giving the player progressively less space and less time to play subsequent pieces. Player manipulates a set of polycubes which fall into a three-dimensional pit (seen from above; the pieces appear in the foreground and fall away). The pieces can be rotated around all three axes, and moved horizontally and vertically. The aim is to form complete layers.