How hard is it to make an App universal? And moving on from that, how hard is it to make it universal and use the retina display? The post on Zen Bound 2 on the main page got me wondering!
Depends on the graphics mostly, coding changes are usually minor. It can require new updated textures for the whole game which is can cost a lot.
Alas it's how is made most HD versions but that should not be restricted to that. There's more space so the interface and game controls would gain a lot of a new design. Just scaling the game doesn't alway fit well the game, it could result is elements that are too big and that could look weird. The speed of the game is a difficult problem too, if you purely scale and your game is based on swiping you require the player is swiping 2 times faster causing possibly fingers injuries. Also for a pure scaling and for same game speed if the collision speed is the same the game is really 2 times faster. For fast games this can be disturbing and some games could face performance fps problems by just doing that.
