yuphoria does not support multitouch games well..u should update ur phone as their is new incremental update available now for better performance

If touch is not responsive you should get your phone repaired. If you just purchased phone recently and it's still under warranty, the cost of the repair should be free of cost. But if touch is only not working for a particular app, then I suggest you contact the developer to report the issue so they can include a fix when their next update rolls out.