You have a handsome cherry and maple box and a set of six dark wenge pieces, each of which consists of a flat 3*2 part with an extra 1*2 bit attached to it somewhere. Now, even without any instructions, it’s pretty clear on this puzzle that you need to inveigle the pieces inside the box without breaking anything along the way. Doing that will make it clear where the name comes from – the top of the box will look like a slightly blocky Yin Yang symbol…
I quite like this design because it straddles the difficulty level rather neatly – not too many pieces, and not many different ways to build the required 4*4*3 shape that needs to be inside the box… in fact there are very few ways of assembling such a block – which to my mind makes this a little simpler as a puzzle because it means bashing through far fewer potential assemblies to see which ones won’t fit inside the box. (That bit usually takes me the absolute longest!)
Finding the exact way to handle said inveigling will cause a little bit of head-scratching, but again, some Think(c)ing is well rewarded.
I reckon this one provides a nice challenge and a pretty decent reward of an “A-Ha!” moment without having to wade through too much slogging – as long as you’re prepared to Think(c) a little.