CD Projekt Red has used its in-house REDengine for The Witcher 3 and Cyberpunk 2077 to mixed results. While The Witcher 3 earned widespread critical acclaim and is generally considered one of the best video games ever made, Cyberpunk 2077 had severe technical problems and was labeled a disappointment by many. For The Witcher 4, CD Projekt Red is leaving REDengine behind in favor of using Unreal Engine 5, though fans have yet to see how it looks in action.