Very cool, but like all games, some flaws. The biggest one I saw was that some of the test inputs are less rigorous than they should be. The level that says your robots have to end with double blues, I could design a conveyor system that would pass all of the given tests, but would fail if it ended with triple blues.

The only reason I'm slightly annoyed: I designed a neat way to avoid failing on triple blues, but then the game never sent a triple blue my way...