Campaign- Playing it.

When I originally played the campaign, it had been years since I played a Starcraft game and it eases you into the gameplay very slowly, staring you off with a handful of units that will pretty much keep themselves alive. As you progress you are given access to more units and the difficulty increases what feels like an acceptable rate. I started the campaign on normal difficulty to get a feel for how the units moved and behaved, and didn't feel particularly challenged. A few times I increased the difficulty just for the experience, and found I could manage pretty quickly.

Many of the objectives in each mission center around collecting research items and foreign artifacts, which allow you to augment your army in interesting ways back on your ship (where you return between every level). Similarly, completing missions earns you credits which you can spend on army upgrades and hiring mercenaries. At first I didn't use the mercenaries as much during the campaign, except in dire situations. I found them costly and like a crutch only for newbs, and so I spent most of my money researching army upgrades. But once I started using these especially powerful units I found them important additions to my army as well as quite fun.

A quick side note: Blizzard requires internet for installation and also requires you create a battle.net account specific to your copy of Starcraft II. It then connects to the internet every time you log in to the game. This continually verifies your copy (you can only have one account per disc) and links your progress in the campaign to your account. Completing objectives in each level unlocks achievements which earn you points for your online profile unlocking portraits and making you look cool. The points don't seem particularly helpful or necessary, but the portraits are neat to unlock as they follow you into battle, which could potentially intimidate opponents.

There are 29 total missions, 26 of which you can play in a single time through. I haven't played through all the missions but they vary in their objectives and tactics you need to use. There are escort missions, survival-for-this-amount-of-time missions, missions centered around just one unit and of course the traditional build up you army and exterminate the other player (which comprise most of the story).