I have just unlocked all relics. So when you start a new game on my save you have a full choice on what power boost you choose.
The best one is infinite ammo imo. :D
Also I nearly found all the hidden squirrels and poster things. Only like 3/4 more left but collecting them doesn't unlock anything anyway.
Download here: http://www.sendspace.com/file/e9eltu or http://www.mediafire.com/download.php?2ahdyovc87md8z3