Probably the single most impressive aspect of the game from a technical standpoint is the incredible real time lighting. The realtime vertex coloured lighting is probably what most people will comment on initially because we've used this to add even more variety and 'mood' to the cities. We're proud of ourselves because we've managed to rewrite GTA from scratch - as well as building everything in GTA2 on top, and still make it run on the same PlayStation. We spend a huge amount of the processing time on 'gameplay' issues rather than throwing millions of polygons around, so we've got complex, interactive AI and fun, elaborate missions. All of the environments are built in 3D before being transformed into GTA2's top-down 3D engine. We've developed a fully 3D editor to build the cities - this lets the level designers actually place the building blocks of the city down, texture each side/lid individually, and then go around placing directional arrows for the roads, zones, police and gang information etc. Everything else is handled through a powerful scripting language which gets compiled before being incorporated into the game.

Explosions
Basically, we've kept a city "level" clear at the top of the map which can't display any building blocks, only explosions. This means explosions have between 12-24 different layers to give them as stunning, and as realistic a look as possible. After all, there's very little that's more satisfying than to be the cause of dozens of massive explosions.