I once tried to write a simple game with UDP in a week as a throwaway test. It went horribly.
I threw it away early. The main problem i had was restoring the game state of all players/enemies/objects to an old state and fast forward the game to the point of time the player is playing (ie half a second before a jump. A little early or late can make the player miss the jump)
Maybe this method is not the easiest way? i suspect it to be but i designed it wrong from the beginning and realized at the end of 2nd day. (so i didnt learn too much or wasted that much time)
For myself and others, What is involved for a simple UDP game and how do i write one? Or how do i solve the prediction problem restoring to state properly.
I'll mark this as CW bc i know there will be lots of helpful answers.