It's a little bit GTA
The comparison is a rough one, but it suffices. Sure, each district is a wide open beautiful cityscape for players to explore. Yes, everyone can grab cars from random citizens. And indeed, increasing your cred with various NPC factions via missions is important. But more or less, the comparisons stop there and are replaced with the persistent online experience so far only found in All Points Bulletin.
Here, when you shoot down your enemy, it's a real person. There doesn't seem to be any PvE to speak of, unless you count the startling deep customization of characters and cars -- all of which can be sold on the in-game auction house. You can even create your own song with a fully fledged music creator. The fact that players can create their own music is kinda cool, sure. But what makes it ten times more awesome is the fact that when you kill another player, they hear a short section of your preferred custom song while waiting to respawn.
Tell me that's not going to create some intense rivalries all on its own, without much help from the actual combat itself. Although, if you're wondering what that's like I've got a handy trailer ready for consumption.
Here we have a game that already sounds like a whole lot more than just the sum of its various unique parts. These different features -- the customization, socialization and combat -- could fall together just right, creating a whirlwind of community and spectacular online moments. I say it's because of these reasons that APB
is much more than just GTA
Online. Saying as much sells the game short, even if it's the closest general descriptor available.