There are two levels in the game and no new fish appear on the first level, but if you are lucky you can gain the necessary mass to move to the second level. When you see “Escape” in the upper left corner, it means that you are big enough and you need to jump out of the aquarium, where the trigger will take you to the second level, but if you are small, it will kill you. (Unfortunately, I didn't have time to make some notes in the game, so the player will not understand this without me)