Everything we know about GTA IV to date

• A targeted enemy's health is represented by a ring of segments on the inside of the aiming reticule.

• Niko can use taxis to get around. If players choose this legitimate mode of transportation, once inside the cab they can enjoy the ride from a variety of camera angles, pay the cabbie to drive faster or simply skip straight to the destination.

• Vehicle-based gunplay isn't limited to cack-handed drive-by style shootings. Niko can now lean out the window - smashing it with his elbow first - of whatever he's driving and fire forwards.

• Niko will be able to listen to LCPD radio chatter, giving him a valuable heads-up on their movements.

• Police cars appear on the radar.