flOw. Good, but needs more.
You will start off small and eat to grow. To move up and down within the ocean you must either eat a blue or red "Bubble Thing". You will then continue going down and eating different life forms to gain size and strength. You will need your size and strength to defeat the different boss which will be at the end of each level.
All of this is good and fun, but that is all their is to the whole game. Eat and swim. it will keep you entertained for maybe 3 hours. But if the creators really want you to keep playing they should have put a bit more content in.