Comes in two flavours: Operation Cube had just the first chapter; Cube+ retains your progression from original Cube and adds a harder second chapter:

• Cube+ Prep
• Cube 1-1 – Cube 1-2 – Cube 1-3 – Cube 1-4
• Cube 2-1 – Cube 2-2 – Cube 2-3 – Cube 2-4