I wouldn't say it's just the chibi stuff, I'll use episode 9 as an example since it is the worst one in this regard. You begin the episode by seeing the elder praying, one thinks "hmm it's his last match, he's probably going through some shit", well guess what it was a gag. The whole match between Rei and the old man was a whiplash of self reflection and emotional analysis - except no, it's about the man doing silly faces and an imaginary bear on the Shogi board. Then the ending, how the man didn't want to give up Shogi. One would think "it's all he did his whole life, he probably loves it", but no, he just wanted to avoid house chores.
The show has all of these really cool elements that could tell a tale of a boy dealing with his depression. Sometimes the show manages to tell us that tale, but it is all too quick at throwing some dumb gag because it thinks it has to?