It's easy to forget that X-COM: UFO Defense came out 20 years ago, which means some players of the more recent XCOM: Enemy Unknown might not realise the latter game is based on a classic, much-loved series. Regardless of your level of knowledge of the franchise, you'll undoubtedly get something out of this fascinating talk about the decades-old title from its creator, Julian Gollop.
In the presentation, which was originally given at last year's GDC, Gollop steps through an extremely in-depth breakdown of the development of UFO Defense.
Interestingly, the design document for the game was just 12 pages long and the first such document Gollop had ever written. It wasn't well received by MicroProse — being described as "poor" — though surprisingly the final game didn't drift far from this initial concept.
That said, some elements were dropped, including a cockpit-like view for UFO interception (which was deemed too much like an arcade game) and the idea of "men in black".
These are just a few of the details Gollop covers, the entire 56-minute talk is packed full of behind the scenes info, observations and game design advice.
Classic Game Postmortem: X-COM: UFO Defense [GDC Vault]