It looked trivial in the beginning, everything does before you actually begin work. You pragmatically promised a cautious feature set, fitting the work to the project timeline and costs. I wish it was the norm, but it's rare to see a hungry builder walk away from an underfunded project.
Somewhere along the way, between garbage input, inconsistent coordinate transforms, and concurrent execution everything went south. The easy plug and play wonderland you were pitched has been replaced by a gruesome truth. In reality your work will rely on a sinister rats nest of dependencies and complicated constraints.
Your nerves are rattled, the project deadline is looming and for the past couple of weeks all you've discovered is one can of worms after another. Team members introduce delays based on the problems they ran into. Managers setup more meetings to ensure the project is on schedule, forcing you to travel and devouring your precious and ever dwindling productive time. Project managers demand resuts even when the product is far from ready to ship, and don't even think about excuses...
SAY WHAT AGAIN
Schedules never get better
It'll be a cold day in hell when you hear a project lead tell you that you've got additional time or that requirements have been reduced. Like rain falling, you can count on budgets shrinking and everyone's schedule slipping right but yours.
Every project is composed of a multitude of smaller tasks and yours is no different. Now it's time to prioritize which features will get executed, and which will be put on the
shelf scrap heap (don't kid yourself).
Slice and dice the work into required plumbing, immediately possible, short term, and larger efforts. Throw bigger efforts into the scrap heap right away. If you work hard, and are lucky you'll complete a few short term niceties before you're done. And you will ship, because that's what builders do.