Oh and regarding the score: I chose not to track or display a score because it didn't feel in the spirit of the game, and besides that, there's no fair way to score it. It can't be based on their common name, as shown in the game itself, for example. You could argue that the only way to win is to always press frog, since all toads are frogs by scientific taxonomy, but I don't want to say folk taxonomy is invalid. But really, I don't think the score matters to the learning objective.

Which is why the game doesn't track it, there is in fact not even two buttons.