Very nice idea! I love how it's both a twist on Snake and a good take on the theme. The fact that it's a long dog it also very funny and cute.
My only real negative thought is that the tail biting mechanic, while being very interesting and well done, is weird to me as it starts as a very satisfying sequence, and ends up looking more like a level restart, as your position is reset, your length too, etc.
Nothing serious, but since it's kind of the main mechanic, I think it would have been better with an implementation that does not make it look a bit strange. Hope you get my point.
Also, more of a detail, but it would have been cool to have a bit more animations and juiciness. For instance, the squirrels could have a little walk animation (either a two frames sequence or some bounce on the sprite), the bones could also move a bit to make them stand out more, with some VFX on spawn, etc. Nothing serious either, but these little details would have make the game muc better imho.
My comment is pretty critical, but don't get me wrong, overall I enjoyed playing the game and I believe it's a very solid entry! Congratulations!