I just ended my single player stint of it now at 1:30 am. been playing since 9 PM. I couldn't play for 2 days after I bought it because I was resolving an issue with my laptop, ending up with the culprit being it overheating and needing a cleaning.
This single player campaign is ridiculous. I've fallen in love with the upgrades feature they added to campaign. It really adds another dimension to gameplay. I was really excited about getting automated refineries. The medivacs are really awesome, especially once upgraded. They really added a lot of good things to the game over SC1. How can you not love a game where the best strategy is to overwhelm your opponent with numbers?
When I play the missions, I definitely get the feeling I'm being rushed, and I *like* that. A mission made me keep up with moving convoys that needed protection, so I was managing the base and thinking on my feet with the convoys. The other mission where I made that screenshot was cool as I had to defend during the night and attack during the day. These are definitely creative missions.
One thing that I'm noticing I like a lot is the improved AI and functionality of the game. Medics follow ground units instead of running ahead. I actually make medics an integral part of my marine force because of that one improved piece of AI. SCV's automatically repair units and structures. You can shift-build multiple structures in a row so that one SCV can build a string of supply depots without you having to pay attention to it. These were just a few quirks that made me annoyed with SC1.
Regenerative vehicles made the mission with the planet going nova much simpler. They introduced medivacs in that one mission, then immediately after, I upgraded them. Dropships that can heal? Yes please. Faster unloading and healing two at once is well worth it. Each mission is unique. Which is really good. I felt bad for Kerrigan during that cutscene of being abandoned. Tychas'(sp?) joyride in Odin was hilarious to watch.
Blizzard is one of the companies that makes quality games, and I have no problem giving my money to them. I just played the mission called Maw of the Void. It was the first mission that I outright lost. I ran out of resources and slowly died.