I recently added an iOS game embryo to GitHub: https://github.com/LarsBergqvist/GravityBall
It’s a SpriteKit-based game in Swift 2.0 where you tilt the device to roll a spike ball around with the aim of smashing an infinite number of balloons.
Yes, it’s an endless game with no more purpose than destroying balloons for pure pleasure. But the major stakeholder for this piece of code likes to play it (my 4-year old son that currently has an obsession with physical balloon annihilation – with an app there’s much less to tidy up afterwards).
The code illustrates usage of accelerator data and multiple gravity fields. The physic’s world has a normal vertical gravity field, but there is also a SpringField in the middle of the scene that interacts with the balloons so reaching the balloons gets a bit harder.
I will use this game template for a complete maze ball game in the near future (do you remember those wooden games from BRIO in a not so distant past when there were no computer games around?) – perhaps with some Pac-Man ghost as enemies in the labyrinth.