I am not entirely sure why this feature was not implemented into the game, did they not think of it? Did they think it would be too much work? Or did they not come up with good designs for it. All of these I can see as possibilities, but I brainstormed through some designs, and I finally got it! I present to you... the Bunkum Sackbots!
http://www.littlebigforum.eu/forum/download/images/f44t4146p31084n2_SCgxkPaU.jpg

I hope you like them! And here's a picture I did for fun, I call it... 'Sackbots Galore!" It also helps you see them from another angle, too.

http://www.littlebigforum.eu/forum/download/images/f44t4146p31084n3_MPgQLSOJ.jpg

To move their heads, (since they don't have necks like Sackboy, sorry Bunkum's heroes .) they have a line that is a shows that their heads are separate pieces from the bodies. There is a screw within the two pieces to allows head movement!