Great game. And I am quite proud of my ~56.000 score (no idea if that is much). Graphics are minimalistic yet pretty and the mario-coin-collect-sound when boxes pop is very satisfiying. And you even implemented a bonus for longer chains!!
Just one minor thing: I felt like the real problem losing this game is the time and not the balance (which is not a problem but the theme was balance, you know?). I never had a problem balancing the board (just reached the yellow bar once), even If I just put any colored box to other boxes of the same color, ignoring the board.
What I want to say: I think you could put up the boxes impact on the balance and put down the time scale. This may be leading to some bigger tetris-like block-constructs, just because the player was forced to put a block on the wrong side of the board to balance it.
I am only talking that much about that one suggestion because it is really the only suggestion I could make. Really well done at all!