The primary gameplay (toppling, black/white) is pretty interesting and I'd love to see a more fleshed out game with more challenging and engaging levels. Though if you wanted to produce a more "thoughtful" game let's say, you could really do with losing the quotes or providing a real reason for them to be there in addition to intelligently implementing a slower pace. Waiting around is annoying.
The levels seem too easy and can usually be completed without much hassle by just wrecklessly going for it, so maybe introduce some different obstacles or threats. If you want to keep a minimalist theme perhaps limit yourself to a certain number of types of threat per stage or something.