I don't know about that game, but my 3835 (essentially the same as the 3870, but the 3870 has Bluetooth built in) can play movies up to around 500kbps smoothly in Pocket TV, in MPG format. Fullscreen looks nice with that bitrate. Still, the files are huge, so I don't use that much. Prefer WMP for playing low bitrate ASF files I rip from my VCR via an IREZ USBLive cable and WMEncoder9.
The biggest problem with the whole 38xx series is crap screens. If you can get one, go for any of the 39xx devices, as the screens are just way, way clearer, none of the 'blue haze' the 38's have in varying degrees. I've seen a lot of both models, and this is safe to apply in general.
