Related: there is a fantastic, oft-reposted, and quite in-depth article about the difficulties faced by developers porting 'Resident Evil 2' to the N64 - the primary challenge being fitting it within the 64MByte limitation, as compared to the Playstation's 700MB CD.
> We dealt with the publisher's requests to add new features, especially towards the end of the project, with aplomb. Rather than an internal attack of "feature creep," these came from the outside. Each time a new feature was proposed, we examined what it would take to implement it and presented an honest account of what it would take, in terms of resources, to implement it.
Just tell the client how long it will take! Of course! This makes me a bit suspicious about the relevance of the rest of the author's advice, given that I certainly don't have access to whatever eldritch magics he channeled in 1999 to gain these powers.
A fantastic and critical read to anyone interested in this sort of thing: https://www.gamasutra.com/view/feature/131556/postmortem_ang...