OK - just got the first certificate in Co-op mode. So YES its possible to get it this way - I strongly recommend barrier although it can be pretty tough if the ball gets fast - which it - of course - got in Level 30. I'm Nr. 1 on the leaderboards now for both time and points. Yeahhh! Second gamer does not get the ach.
Last edited by kookyscientist; 05-08-2009 at 07:54 PM.