Just played through it again. Now there are a lot of assets, three sections of a city and pretty detailed, although low texture and polygon quality.

So....they licensed the Renderware engine and apparently modified it pretty heavily. That was about in 1999 and the game was released in 2002. As far as I can see they had a team of about 15-20 people overall, they used to be DMA design and were bought over by Rockstar. It seems a mammoth task though creating all the assets/gameplay/levels/coding/scripting in such a small time. What was their secret?

they had massive, massive whips

I haven't played the game in forever, but I'm guessing they heavily re-used assets, that and it's PS2, so low textures, low poly models, etc. That kind of artist count in that era wasn't all that uncommon.

When a team is considered big? 50+?

I got super impressed when I read that book w/ lots of post mortens (postmortems from gamedeveloper), and the team of the original age of empires was like 25 ppl if I remember correctly..Id expect it to be made by 70+ ¦D

Just played through it again. Now there are a lot of assets, three sections of a city and pretty detailed, although low texture and polygon quality.

So....they licensed the Renderware engine and apparently modified it pretty heavily. That was about in 1999 and the game was released in 2002. As far as I can see they had a team of about 15-20 people overall, they used to be DMA design and were bought over by Rockstar. It seems a mammoth task though creating all the assets/gameplay/levels/coding/scripting in such a small time. What was their secret?

I don't see that much of a challenge. It's all about finding the right workflow, in particularly having good concept artists and skilled mappers / modellers. Actually Rockstar Games stated in an interview, that they have perfected their workflow to such a degree that they could release a new map of the size of GTA V's by every year. Not sure if they count in research though; half of Los Santos' buildings are "inspired" from real buildings in L.A..