I saw that posted on a backpacking forum a while ago. There are several things about it I don't like, but if you really want a long gun that's light, it might work okay. I know nothing about its reliability or accuracy, but it doesn't look like a comfortable gun at all. I'd probably just grab a Ruger Single Six and throw that in my pack, quite frankly.
A Marlin 39 does indeed break in half, but it's considerably heavier than this gun.
Honestly, a Ruger 10/22 is a fairly light and compact gun, especially with a synthetic stock. It would be a lot more comfortable to shoot and very reliable. You could even put a trigger kit in to replace the terrible stock trigger and still spend about half as much as this guy costs. I'm not terribly familiar with the bolt-action options out there, but I do know there are many very nice guns that would be even lighter and just as accurate, and probably even more reliable.
That said, it could be better than the AR-7 style guns out there, which seem to have widely varying reviews. I'd love to read a few good reviews of it before I write it off completely.
The lack of a trigger guard does not sit well with me at all.