Original sentence: Half-Life: Opposing Force (Commonly referred to as Op4 or OpFor) is an expansion pack for the popular first-person shooter Half-Life, developed by Gearbox Software and released by Valve Software on October 31, 1999
Edited sentence: Half-Life: Opposing Force (Commonly referred to as Op4 or OpFor) is a critically acclaimed expansion pack for the popular first-person shooter Half-Life, developed by Gearbox Software and released by Valve Software on October 31, 1999