I really like the two-seasons gameplay and the narrative of a penguin longing for Summer :D
The changing music based on the scenery is also quite nice, and graphics are well fitting :)
The gameplay is really nice, and with some more polish it could become a pretty fun game. It took me a while to understand the "build momentum while swimming before you jump", so I got stuck for a while before the first checkpoint. Then I passed it by chance without really knowing how, and got stuck at the second one - I finally got it when reading comments here, so I guess it needs to be made clearer in game :)