This game was so cool but confusing at the same time, found a small glitch close to the 5th "checkpoint" that both my right and my left blocks started to lose and gain color in a patern (srry, not native english), the lore was amazing and the sprites of the creatures completely beautiful, especially the ozobs (I think that's how they are called), i spent 30 minutes feeding just one rotter to see if I could find the secret rotter, any hint of how to get it? lovely game and I've made several towers now :)
So glad you enjoyed the game!
What you encountered was actually not an error. Blocks lose their highlight when they are outside of the "Construction Zone" so what likely was happening was your tower was slightly leaning too far. During our trailer you can see blocks lose colour like this as the tower collapses. Often when blocks start unexpectedly going dark it is a sign of imminent collapse...