The answer? All of the above. Aggressive players will enjoy laying waste to towns with warships and cavalry, and forcing the pirate factions into submission through brute force which will allow their trading ships free passage. Sneaky players can plant saboteurs to disrupt manufacturing facilities or pickpockets to siphon gold into their own coffers without the other player being any wiser. And pacifists can quickly expand and establish themselves with the most diverse infrastructures on multiple islands and secure lucrative trading routes.
You can get away with focusing on conquering the map through force or occupying the most islands first. But that's only if you're playing by yourself or against the computer on easy. Just about every civilization sim offers these sorts of combat and building aspects of gameplay. But it's rare that you find one that encourages you to explore both without making you feel frustrated and boxed in.
You can also butt heads with up to four players online in either co-op or versus modes with various conditions for victory. But if that's not your cup of tea, there are lots of single player missions to dig into for a more structured and shorter session. In one mission, we found ourselves stranded on an island with a huge volcano and we were charged with upgrading our colony and building a ship so that our people could escape before fiery lava death rained down on our town.
Unfortunately, not all of the single player missions are this exciting and a lot of them have similar objectives. Also, no matter which mode you play, your colony will almost certainly end up with the same boxy look as the cities you've built in other sims as you attempt to crowd as many housing structures near the ones that provide benefits to your people.