Originally Posted by Main Features
Gameplay
* Niko can use a mobile phone to recieve calls and phone his contacts. He can also use it to call taxis and purchase weapons. The options presented on the phone's LCD are Phonebook, Messages, Organizer, and Camera.
* Pedestrians smoke cigarettes, read books and newspapers, drop litter, talk on mobile phones, walk in and out of buildings, and generally act like any normal pedestrian would.
Phone
Mobile phones are a big part of Grand Theft Auto IV's gameplay.
* It is possible to climb and descend telephone poles, and exterior fire escapes.
* There are many different animation sets for breaking into cars. One of these involves Niko smashing the side window with his elbow, climbing into the car, and then hotwiring it.
* Niko is able to manage his funds at ATMs.
* GTA IV features multiplayer, but it's "not a massively multiplayer game," according to Rockstar's creative vice president Dan Houser.
* It is possible to surf the internet in GTA4 via internet cafés. It is available from any computer in the game, and provides a hub for all sorts of interactivity within Liberty City.
* The camera angle behind the car is closer than it has been in previous GTAs. This allows you to see more detail on the cars, and more of the verticality of the city.
Unique game moments
The euphoria package provides unique game moments for players.
* In GTA IV, you will gain a police wanted level for any crime that you commit, providing there are witnesses present. The police can only chase you if they know where you are, and they need to see you to know where you are. If you escape the search area marked on the radar without being spotted, your wanted level will disappear.
* In terms of scale, GTA IV is about the same size as GTA: San Andreas, but the map size is considerably smaller. This is mainly due to the fact there is no desert or countryside in Liberty City. Liberty City in GTA4 is the biggest city R* have ever created.
* Every street in Liberty City contains a street sign with a name on it.
* It is possible to do more than one mission at a time. For example, some missions take place over several days and may involve waiting for phonecalls or attending interviews, and you are free to carry out other business during the waiting period.
* The story can be told in a number of different ways. Rockstar are trying to give people greater freedom and sense of control over their destiny. You now have a lot more choice in what you want to do.
Technology
* Grand Theft Auto 4 runs on Rockstar's proprietary next generation game engine, R.A.G.E., allowing for an unprecedented level of realism and interactivity.
o New sunlight and weather effects which give the city a whole different appearance as the time of day progresses.
Volumetric Lighting
New volumetric lighting effects are evident in the first trailer.
o Volumetric lighting effects allow sunlight to stream realistically into dusty interiors. Police spotlights will likely benefit from this effect as well when helicopters kick up debris.
o Normal (bump) maps will provide much more detail in models than the underlying polygons, as well as giving materials more texture and depth.
o Road and building textures are more varied than in previous GTAs. On some roads you will find potholes, metal plates (etc) where the road has been dug up.
o Modern pixel shaders give water, glass, cars, etc.. more realistic reflections and shininess than the earlier games.
o In cars, you can see real reflections on the rear and side-view mirrors.
o There are no load times in GTA4, not even during exterior-interior transitions (and vice versa.)
* GTA4 uses euphoria, a fully procedural animation package created by NaturalMotion. The core technology is the Dynamic Motion Synthesis (DMS) system.
o Variations in the terrain are met with realistic changes in the walking animation.
Hanging on to trucks
Characters have the ability to hang on to the back of vehicles.
o Unique game moments. Animations are created on the fly, so each player's experience will be unique. Gamers are no longer subjected to pre-recorded animations.
o Characters will react realisticaly to being hit with gunfire, cars, and melee weapons or fists.
o Players will be able to push people out of the way, rather than "floating" past them as in older games.
o Falling/thrown characters will react as in real life- They won't simply be limp, lifeless ragdolls. Nor will they use a canned "super hero" animation like before.
o Characters (and players?) will be able to hang on to helicopters and trucks, which will swing them around as the vehicle moves.
