The story is quite simple: you get stranded on a deserted island after some experiment gone bad during the Philadelphia Experiment. Deserted is not quite true as zombies, bears and wolves are keeping you company and looking out for you.
It's a survival game where your goal is to find a way out of this apocalyptic island while trying to stay alive. You'll need to find resources, craft tools, find food and build all kinds of stuff to help you complete your journey.
Radiation Island is a mashup between Minecraft, Myst and GTA. Graphics are good looking and the environment is huge. There is a lot of details in the gameplay that makes the experience enjoyable. For example, the more you move, the hungrier you'll get. At night, when it's cold, you can warm yourself a bit by moving or jumping up and down.
The is a lot to explore and craft. How you manage your resources will have a big impact on your faith on this island.
Luckily, when you start your game, you can select 3 levels of difficulties. The easiest will let you explore and learn about the game's complexity without being concerned about hunger and being attacked.
From the description, it looks like when you complete the adventure, you'll unlock a multiplayer feature, letting you play with other players online.
Currently prices at 3.49$ in the Canadian AppStore, Radiation Island is worth every penny. A recent iOS device is preferable as the game has a lot of graphic details.
I am using an iPad 4 with Radiation Island and it's running smoothly. I will try it on my iPhone 6 to see if the rendering looks better.
Have fun surviving!