App (Game) lagging on the ipad mini retina display

Hi all,

I have an ipad mini with retina display cellular and wifi (32GB).

I am having trouble playing my regular game (Battle Camp) which i have played on my iphone 5 and ipad mini (non retina) before smoothly. I just switched to the retina version a week ago and the game is lagging frustratingly especially when i do 7 combos or more. gems would start dropping down to the board in a slight lag and the damage numbers would multiply in a lagging fashion.

I do not have such problems with my previous iphone 5 and ipad mini (non retina).

Have reset the ipad mini countless times and tried reinstalling it from app store. I even brought it to service centre but they claimed they could not do an exchange for me as their diagnostics test found nothing wrong with the ipad.

This is the only app that is lagging for me in this ipad.

what do i do next.