Thanks for your feedback! We didn't do enough to explain how to play which is why it feels random. We learned a lot from this game jam, and if we did this game jam again we would definitely focus more on teaching the player how to play and making less assumptions about what the player should figure out.
But if you were interested, it's actually not random! Each word corresponds to a weight and the words are introduced in such a way that you will learn them, for instance, the first level always has words with weights -1, 1, and 0. The hope (without implementing it because we didn't teach it) was that if the words are {bz:-1, bzz:1, bzzbz:0} then the player could pick bz or bzz and learn from that choice what weight the other word is. In the future we would take more time to teach the player how to play.