I do agree that paper was lengthy. The key to solve these type of papers is "Selecting proper sequence of Questions". Theroy has been major part of this paper since few previous attempts and it was asked for around 35 marks every time. It would be pertinent to note that, if you are good at theory and QT, then passing was not an issue in this question paper.
Managing time through "easy to tough" approach would have made it more comfortable. Nonetheless I would suggest you to cover the marks lost here; in remaining three subjects, by proper planning and effective time management while writing exam. Wish you all the best.