Cloud gaming relieves gamers from acquiring highly configured gaming hardware to smoothly play high-profile games. To this objective, cloud gaming platforms operate cloud servers that receive inputs from client devices, render gaming graphics, and stream the gaming scenes back to the client devices in real-time. While significantly expanding the gaming industry, this business model imposes high demand on the Internet that transports gaming video for good user experience (QoE) with a typical requirement of more than 10-20Mbps bandwidth, 100ms or less latency, and less than 5% packet drops. In this paper, focusing on two leading platforms, Nvidia's GeForce NOW and Microsoft's Xbox Cloud Gaming, we systematically profile and compare how cloud games adapt their streaming characteristics to client settings (including game streaming frame rate and graphic resolution) and network conditions like bandwidth, latency, and packet drop. Key insights are obtained such as Nvidia's GeForce NOW optimizes its game streaming frame rate and graphic resolution for a smooth user experience, particularly for users using its native application; Xbox does not reactively adapt and shows better tolerance for poor network conditions on PC browsers compared to its proprietary gaming console.