The Game Pattern
Your team is in a trance about a fixed date. On that date, the team has to present a working product with an ambitious feature set. As a project manager, you do not have a clued team and will be able to meet the deadline.
How To Play
Create a project dashboard page and start measure team velocity.
Break your work into one-week iterations. Develop by features. At the end of each iteration, the whole feature must be done. Not just code, do not forget about tests and documentation.
Keep the focus of iteration only on features.
At the end of an iteration, do a mini post mortem analysis as input for the next iteration. Remember, your focus is working feature(s) at the end of an iteration.