The Obstacle Kubo has to overcome is the Giant Skeleton.
This is my entry for the "Kubo and the Two Strings" contest. This one was really fun for me to make and I went off of the rails a bit by starting to experiment with some new brushes. It's based off of the scene where Kubo and his friends are looking for "the sword unbreakable" but activate a giant skeleton with a head full of swords by mistake.
I really liked this movie and I'm a big fan of Laika films in general. If you haven't seen this movie then I highly recommend it. It gets the IsaacChamplain seal of approval!