I love the music in this game, it's incredibly tranquil and the pastel colours work really well with it. What's drawn me to it though is the seedlings and 'asteroids'. The shape and use of the seedlings reminds me of the antibodies. They both protect the cell they've come from and are both a kind of 'Y' shape.
These videos are good examples of this:
Close up of seedlings and tree: 1.10 - 1.20.
Example of movement as a group: 0.25-2.00
The game 'Osmos' is about growing by engulfing other cells that are smaller than you. Its aesthetic reminds me of a night sky and it's translucency mimics that of the jellyfish I was looking at previously. The changing colours and patterns inside the cells are what really give these little circles life.
This video is long but it has a bit of everything from the game: