I've been through two of the chapter 2 missions, and my impression of this game is growing more and more favorable. You can build bases underwater! I made the same damned mistake as when I first tried to settle an island (you don't start a base with the conventional build buttons, even if it's underwater), but it was nonetheless pretty cool.
I had my problems, though. A scripted event in the first campaign mission turned my fish into rotten fish and killed off my whole town. I had to start the mission over. I think the purpose of this was to teach me to use and rely on trade routes, but none of the other factions sold fish, and the game never told me that my underwater base's functional food could substitute in a pinch. Still, you live you learn.
I actually really like Anno 2070's production system - you harvest raw materials to make other materials, which can make other materials, which can go into special buildings and units. However, I'm definitely going to have a long way to go before I master the economy. Matching supply to demand is a major pain (the classic weakness of all centrally planned economic systems), and my credit income fluctuated unpredictably. While it seemed to generally grow alongside my population, it would then spike up and down for no discernible reason. What I think is going on is that my citizens happiness varies based on my current stockpiles of luxury goods, and that affects tax income, but I was never actually able to boost luxury production high enough to see my income stabilize. In fact, trying to do so wound up raising my expenses unacceptably.
It was only in retrospect that I realized I was probably going about it the wrong way. In Anno 2070, you are limited in where you can build your various types of facilities. Residential housing has to be within a certain distance of a city center. My income peaked at around the time I filled up all the available space around mine. But, instead of trying to build more luxuries, what I should have done is just build a second city center and increased my population of basic workers (advanced workers pay more taxes, but need more luxuries). Call it a failure of imagination. Because, up to this point, I'd only needed one city center, I'd gotten in the habit of thinking of them as a "one per island" building, but there's actually nothing in the rules (as far as I can tell) that says that. I'm going to chalk that up to an understandable rookie mistake.
I have a feeling, though, that I may also have underestimated the corporate faction. I dismissed them as a bunch of short-sighted goons, but I'm pretty sure they generate more income per citizen (actually I just checked the wiki, and it turns out their advantage is lower maintenance costs - which still would have helped my balance significantly).
I also got my first taste of combat in the second Chapter 2 mission (an AI, called F.A.T.H.E.R. gets infected by a computer virus, goes rogue, and takes over C.O.R.E - those scientist guys sure like their clever acronyms, though I couldn't tell you what either means). I'm pleased that it seems pretty basic, and thus won't necessarily require a great deal of sophisticated RTS tactics on my part, but actually building a warship required a huge amount of infrastructure and credits, so I'm a little worried that if I do poorly in battle, I may screw myself beyond my ability to recover.
Overall, I am hugely optimistic about this game. I just can't wait until I stop stumbling around blindly and actually get good (that'll probably take more than 20 hours, though - this game looks super deep).