Snapz Pro X will record video, but the file size and saving time will be massive for a whole game – almost real time, in my experience.
It's a moving screen grab. You drag a window over the application in which you are watching the game. Anything that goes through that window is also recorded, like a cursor. So, you can't really be doing anything else while watching the game.
Mac Pro dual-2.4 GHz, 10.13.6, 24 Gb RAM, 250 Gb Samsung EVO SSD/Velocity Solo PCIe card, 2x3Tb Seagate HD, 1x3Tb Hitachi HD, Dell 2408WFP; Canon PIXMA iX6550; CanoScan 8800F; MacBook Air 1.8 Ghz, 8 Gb RAM, 10.14.6, 256 Gb SSD; Vodafone Home Hub/BT Wi-Fi Extender.