I own a copy of Snapz Pro X 2. It's very good and has many recording options. I can record Halo on my first generation iMac g5 (the one with the 64mb fx5200) with reasonable graphics settings at about 20fps. At low resolutions though, usually 640x480 or 800x500. It's good, not as good as Fraps on Windows for recording games though, unfortunately. It's extremely processor intensive, so you're gonna need a g5 for a decent game recording i'd imagine. I guess that always depends on what type of game you're recording. Marble Blast should be fine, hehe.