Ikachan takes place into the underwater world, where you have to control a little squid named Johnnie. Your aim is to save the world in which you live, too. The area in which you live became isolated by the rest of the ocean after a series of earthquakes and the food shortage requires you to save the inhabitants.
There is only one big level in this game and there are a few important inhabitants of the world and you must progress and increase your level in order to be able to do everything you are required to. Whenever you want you can save by sleeping in an oyster.