Sentence:  Moreover, where three lives and a sparse availability of extra life-giving '1-Ups' marked the 1991 experience, the iPod player is offered an unlimited number of <WSD>continues</WSD> with which to progress through the gameworld. 
Meaning of the word marked with <WSD> tags:  An option allowing a gamer to resume play after (game over), when all (lives) have been lost.