I have one of these.
With the new Cacko 1.20 ROM, the files it records play very nicely on my C700. (They did not play with the factory ROM) .
I have never gotten the files to play properly on anything else. I tried them on a Windows machine in a store, and after an automatic Windows Media Player update, it did play the video, but I do not think it ever played the sound.
Despite loading every codec I could get my hands on, I never got the files to play in mplayer, but in theory it should be possible to make it work.
If you can read Japanese, and you have a Japanese version of Windows, there is a patch that is supposed to correct the files that it makes. I was not about to attempt a flash upgrade based on software I could not even read.
You can also change the default settings to correct color, increase frame rate, etc. Again, this S/W is Win only, and in Japanese. It does run under Wine, but again, I cannot read it.
Also note a few things:
1. It DOES NOT play back. It has video out only for on screen displays.
2. The on screen displays are in Japanese.
3. It has no tuner. You can program it like a VCR, but you can only select which of 2 video inputs to record.
For basic operation, and even setting the timer, if you can program a VCR, and your IQ is greater than pi, you can figure it out even if you do not read Japanese.