Very different from the first, more to do
It is very different from the first, the big thing being that spreading is now an action, rather than a sort of random event based solely on qualities attained.
The strategy is changed a lot from the first.
Actively trying to spread and how you spread is much more important than fiddling with your modifications. I think people were not expecting that at all. It major shift in strategy has (obviously) put off some people. But, once you figure out some of the new variables, what's important in this game (and what isn't), there is more to do than the last.
It is now much less like the natural spread of a virus and more like an (malevolent) entity actively trying to spread a virus.