How was the certification exam?
The certification exam was a mix of questions based on theoretical concepts, case study, keen observation of weblogic etc. There was a good percentage of easy questions but to pass the exam you need to make sure you answer difficult questions are correctly. There were 77 questions and passing mark was 64%.
What were the important topics covered?
A good number of questions were on new features of Weblogic 12c so I would suggest to have a good understanding of them. There were questions based on basic concept of weblogic which we tend to skip very often ;-) Install weblogic environment and do some hand on before attempting the exam. It is must because there were questions based on case studies which cannot be answered merely by going through theoretical concepts.