So at the end of the playtest report for the Stargrunt game I ran last night, I mentioned that I was concerned on a number of fronts, in that close combat, artillery, and possibly anti-air fire all felt just a little bit 'off'. Went and re-read the rules this morning, and here's what I'm seeing:
First off, close assault. The biggest thing, looking back at the rules, is that initiating a close assault takes two actions; thus, we can't do that thing we were doing where we make a non-combat move six inches towards the target, then initiate close assault, guaranteeing that you'll get there in one combat move. This makes final defensive fire a lot more likely to happen, which is great for Terran. On the other hand, it really exacerbates the problem with Zerg being suppressed - if you have to spend an action to try to break suppression at the beginning of your activation, there is no way you can close assault. I really think a free suppression removal attempt at the beginning of Zerg activations at morale levels where they have to close is probably a good plan.
The other thing we did wrong with close assault was casualty resolution with regard for stunned troops. The way we were doing it, we were resolving the status of casualties at the end of each round of close combat. This in incorrect; the book states that a casualty is out for the rest of that "close combat resolution". We interpreted this to mean that round; however, the Ending Close Combat paragraph opens with "After the first round of close combat resolution..." Thus, a 'resolution' is the entire process from charging to one side breaking and abandoning an objective, while a round is the process of pairing off and making opposed rolls for each pair. Therefore, casualties aren't resolved until one side breaks, and stunned individuals on the losing side may 'come to' out of unit coherency and surrounded by the enemy. Thus, 'stun' isn't just "Oh hey, the squad leader's fine." It's roughly on-par with being an actual casualty.
Finally, there's an important line in the close assault modifiers table that states that if in cover, the defenders get a 1-die shift during the first round of that close combat. Oops.
As for artillery, I found a very important line in the artillery rules that the spotting unit must have line of sight to all three points nominated (the two dummies and the actual incoming). This makes overlords and other aerial units excellent spotters, and also gives hills some value (besides as places to sit at the bottom of and fire up at the enemy who are trying to take it...). However, we did do it wrong last time. Still couldn't find a mention of the Observe action, though, outside of the list of actions at the beginning of the book.
Finally, I screwed up the firing at the overlord, in Terran's favor, actually. We used the rules for firing on point targets with heavy weapons from page 39 and the guided missiles section on page 41, which seemed like the right thing at the time... but we should've been using the "On-Table Anti-Air Fire" rules from page 49. Under these rules, Terran would've needed a roll to acquire the overlord as a target. Then the overlord would've had a chance to take evasive action, allowing it another chance to avoid the fire, after which Terran gets a chance to actually fire the missile, and has a third chance to miss. It's kind of ridiculous really. Terran gains two things from this: first, if an aircraft takes a hit, the pilot has to take a confidence check at +2 TL or decide to purple and GTFO. This means you could potentially drive the overlord off the table, denying the Zerg their command squad, transport, EW, and artillery support. The other thing Terran gains is that when hovering in place, the overlord suffers a negative die shift on its ECM roll. But the Terrans now need more successful rolls in order to actually take a shot at it, so this is a really bad change for them. Considering that their AA fire was already horrifyingly ineffective, we might not want to change the way we played it to this rule.