Following feedback I've got from different sources, I've redid the on-screen controls to a much more intuitive 3D compass (hopefully!) and added an undo system with 10 undos per level.
I've reworked the level rewards to match the undo system. Now, you get a gold star for completing a level without using undo, and a silver star otherwise.
Play the improved Snake Island now! And don't forget to support the snake with a fruit or a coffee ;)