Complex sentence: The Commodore 64 version was programmed independently by John Darnell, and after the original project had been abandoned work continued on the C64 version which was released as "Star Paws".
Split into simpler sentences: The Commodore 64 version was programmed independently by John Darnell. After the original project had been abandoned, work continued on the C64 version which was released as "Star Paws".