This is a very pleasing game. As casual as can be...nothing really attacks you or anything (except for those ♥♥♥♥♥♥♥ crabs, but whatevr, lol). Basically, you swim around catching fish, finding treasure, and taking pictures. You can automatically turn those pictures into screen savers if you like, which is a nice feature. You can upgrade your various gear as you gain cash via all the aforementioned activities. There are also quests which are basically catch x amount of this type of fish, find this many treasure in an area, etc...
Essentially, the game just gives you a nice relaxing experience with soothing music and beautiful visuals, with some stuff to do to ehance the experience. You can unlock free roam via completing areas, which then gives you total freedom to just check stuff out.
At this point, I have finished all the area quests, and probably will get the 95% accuracy achievemnt in my next playthrough. That said, I'll probably keep this one downloaded for those times where I really dont know what I want to play or just want to unwind a bit.
Very much recommended. Probably 8 speared fishies out of 10 with a photo of a blue whale mixed in.