Minecraft has a good amount of combat focus with the difficulty on anything other than peaceful, and there are PvP servers as well.
Maybe with PvP, but hardly otherwise. There's so few enemy types, and no variety in combat (either I hit it with a sword or I shoot an arrow at it, woo). On top of which, none of the enemies are really all that dangerous.
I've played Terraria since last Friday, and by Sunday night I'd already seen everything it has to offer. It's a fun game with some good potential, but as of right now there isn't a whole lot of content. I imagine that if they do some content updates, this will become a very good purchase. Personally, I'm waiting to see if it goes on sale during Steam's usual summer madness (I played a beta leak originally).