Leaked screen of GTAIV

[A Black Falcon]

Oh and by the way:

2 did use a number, though. ... and GTA 3 didn't call itself "III"... :)

I think it hold up fairly well. And GTA2 was quite a bit different from the first one and the London expansions.

GTA2, for one thing, was set in the FUTURE. And had a generally futuristic and cyberpunk feeling to it. You could join different factions, pedestrians and other vehicles would actually doing things instead of just being decorations, and you could be attacked by more than just local police [SWAT team and army units].

GTAIII, Vice City and San Andreas all had a very similar feel [though different settings and time periods] as well as gameplay. Plus, they all pretty much used the same engine, with some tweaks being made with each iteration.

Many sequels are far less different than the three "GTA 3" games, though... really, this could as easily be GTA 6 as it could be GTA 4.