It's a really cool mashup, though not finishing words immediately feels weird but I have made a game with the same thing a while ago, so I can't really complain...
I'm ashamed about how long it took me to get that z axis joke.
Thanks! I agree, it doesn't feel quite right. Maybe a bit more interesting than flapping when completing a word, but I'm still not sure.
I was hoping to get a bit fancier with Rival Bird's animation (or the camera) to make it more obvious that they aren't just magically clipping through the obstacles or something, they are just living on a higher dimensional plane.