The painterly aesthetic is not something you see in games often; I like it in this! I Wanted just a little more oomph in the grapple reeling/swinging action but I understand that might have broken/bypassed the puzzles.
The red arrow graphic pointing between the yellow and grey/blue blocks could be a little clearer, I first thought it meant hitting the block would change the color, not realizing that I had to be standing on the source yellow block. Swap the red arrow out for the grapple graphic and maybe add a little robot on the source block perhaps?