Cut the Rope: Time Travel is the third main game in Cut the Rope series. While the game retains the same game mechanics of the previous games - i.e. you need to cut the rope to deliver candy to cute creature Om Nom while solving physics-based puzzles, - the game introduces several distinct gameplay elements.
The first one is related to the game's story: Om Nom finds a time machine and gets transported to different time eras and locations - Middle Ages, Renaissance, Wild West, Disco Era etc. In each era he finds another creature (his ancestor) who's hungry for candy too. So now there are two creatures and two candies in each stage, and new gameplay mechanics take advantage of this: for example, there is a copy-candy which follows the moves of another candy, or candies that can be connected to each other (think lasso of Wild West) etc.
Secondly, there are new hazards and new time-related abilities: time freezing button, clocks with rotatable hands that change the position of certain objects and so on. New level packs (time eras) were released for the game for about one year since its initial release - a total of 11 level packs.