Got this the other day & been playing it but its been a bit glitchy as in sounds repeatedly playing at certain points. Now its completely messed up near to im assuming the end where you go up in an alien spear & it throws you out of the top, an alien grabs you then they all blow up & you have to use the defibrillator to revive yourself and make your way to the helicopter then it goes black for me, causing me to turn my xbox off & back on.

Why would this be happening?