I am developing a website where user can create their own game which can be joined by other users as well. It's a simple maths game which will shoot equations based on time or count specified. I want that moment user create a game, it will be listed in "current Games" section. Other users can check out the list and select the game to join. After game is created, creater should have a screen which should be having his name with display pic. Now gradually as others start joining the game, list should updated automatically. Once enough users are there i will start the game. The same list should be displayed to other users who join the game. Once game is over all will be displayed a summary list.

I have gone through couple of threads but could not get clear idea. Do I need to use comet or other technology to create such game or simple PHP, Ajax or Jquery will suffice ? Also I want my website should be mobile compatible so i am designing it in html5. If i create this game using just Ajax then will there be any performance issue while playing through mobile. I am not much experienced so just need guidance for what should be appropriate or use for my requirement.