Hi,
A good idea about races between different animals, it shows their inequality in one thing well, that is, each animal has its own advantage, some in the sky, some in the water, etc.
I definitely laughed at the fact that for a shark, racing is a defeat :D.
In fact, the rabbit wins 100%, it is possible to win for the bird, if the rabbit gets stuck, for example, by hitting a stone, that is, if you choose the rabbit and simply hold down the right and up buttons, then the victory is yours :).
Perhaps for such races it would be good to consider more mechanics that would take into account the strengths and weaknesses of each animal, for example, if you play as a shark, then for the shark the entire location below consists of water, in which there are also obstacles, if you play as a rabbit, then it swims slower than a fox, if it is a bird, then give it a faster flight, but also obstacles in the sky, for example trees, etc. That is, put all animals on equal terms where the one with the best skill wins.
Overall, I liked the idea, it was fun, congratulations!