The starting point was based on the notion "too blank a canvas". As a lecturer, I teach wide range of disciplines related to Games Design -- leaving me a jack of all trades, master of none. My first aim is to find an area which I'd like to focus on.
A quick glance at a fellow MA student's 3D modelling specialist work made me realise that there are a number of areas where the jump to bleeding edge would be too substantial at this stage. So, I threw a few ideas down on paper:
My initial emphasis had been casual, mobile gaming (with the emphasis on 'casual' and the other emphasis on the comma). Over the last week, though, I'd been feeling too pressured by my paid work (which is moving more towards mobile development) and wanted to make sure that I don't get pushed into a corner.
After a quick break I started to meander off into a specific game idea (which definitely deserves further development), based around the need to evacuate a building at high speed, making split-second decisions and dealing with debris & stuff like flickering lighting. Essentially a cross between Mirror's Edge (with less Parkour) and Pakoon 2.Many.
Course Leader (and all-round legendary super-genius) Josh Taylor hit the nail on the head quickly: I'm a one-man development team. I may not be able to compete with the likes of DICE but I can use the range of skills to my advantage...