When opening my apps they close and go off

Hi, Ive had an Ipad 2 for about 2 years now, and still does its job on the internet and that, but recently I was playing a game called First Touch 2014 when it just froze and went off, and its been like that for 2 weeks as soon as i click on the game, just shoots straight off, but the main one that i want to sort out is my Game Center, from last night it just shoots off, as soon as i click on it, bang straight off, you see the points for like 2 seconds, and then straight off, to the home screen,

occasionally when i'm on the home screen, it will just shoot off the page, and go straight to the home page but i can still open the safari app afterwards , but dosent always open right back to where i was,

its more the game center im after sorting, I dont know why its playing up like this,

If anyone could help that would be much appreciated,

Thank You

Gareth.