Wow the game is really good and polished - pretty crazy how much you achieved in a Game Jam. I also liked that you included the dash ability in the race, so that the player has something to do instead just watching the race.
Two improvement suggestions if you want to do a patched version at some point in the future. :-D
1. The tutorial has a little bit much information at once, maybe postpone some information to later (like breeding for example, which is not needed immediately anyaways)
2. Some warnings would help. A warning that a bunny will retire soon - and also a clearer text when no bunny is eglible for a race. I only realized later that his means, every bunny is retired. Maybe I missed that in the tutorial - like I said it was too much information at once for me :D