It seems plausible (what LesManley pointed out), that the game could be "unfinished" according to the designer. Unfinished games are usually obvious in that they flip, but you can clearly see that they could easily be "so much more". IJ4 could fall into this category, IMHO.
But I will agree with goatdan in that the captive ball/scoop mech is a wicked cool feature. I wish they used this more in other games.