$2 million is not a lot at all for a modern game... it's just the basis to get started really. I worked on PC games that cost $60 million to develop. And we are talking about 4-5 years ago...
There is a reason why today the creativity is dead: nobody wants to risk losing money. So much easier to make NFL 13 game by changing the number "12" into "13" and to write a press release stating how many imaginary things have been changed. That's low risk development.
This is high risk, but real creative stuff, that's why they need the base to start... Plus Braben's company is rather small. 300 employees for a game dev is not a big deal in this day and age.