Thanks! The ability to eat yellow square was implemented in a rush, because I had 15 minutes left until deadline, so I'm not surprised it's buggy :)
Overall, my initial plan included additional block types that you could swallow; eating those blocks would let you spit out some of the blocks you have in your belly. I think it would allow more interesting puzzles, because I have a feeling that the game would get boring pretty quickly if there was only one mechanic available. Anyway, time was an issue, so I had to scale down a lot.