Games that need a sequel

[Pigyman]

It can't. It's a 2.5D side-scroller.

Yet, they made lead designer of SA1 and SA2 the head of Unleashed's development.
Also, it will feature an overworld, something SA2 didn't even have. This overworld could feature full 3D movement for all we know.
Not having the same movment style doesn't automatically demote it.

Well, it has to meet some requirements to be SA3. For example, both SA and SA2 had multiple characters to play as, each with unique ways of playing (such as platforming, shooting, treasure hunting, or...fishing) I don't know much about Unleashed, but I'm pretty sure that's not in there.