I bought this on a recent trip to Paris (from Tumbleweed - recommended highly) and it took enough time to solve that I'm happy with the purchase.
If you examine all the pieces, you'll see that there seem to be four pairs of pieces, one of which is the reflection of the other. I spent a lot of time trying to form those pairs into shapes and then assembling those shapes.
That didn't help.
In the end, this is what it looks like, with the pieces carefully pulled apart.
The cube was a bit tight getting it into the box one way, but when I rotated it 90 degrees it slipped in just fine - obviously just a tolerance error.
All told, a fun puzzle that definitely took me more than a few days of trying on and off.