By far – by far – the biggest change is that units can now shoot and move independently of one another. In PG, when you selected a unit, you had to move and shoot in the same action, before selecting another unit. In PC you can move a bunch of guys, and then shoot with them. Or shoot with a bunch of guys, and then move them all. Including artillery. That works a huge change in how the game plays. So for me, it plays only sort of like PG, although it looks just like PG the metagame (upgrading your persistent army, etc.) is pretty much the same (as Piemax2 said, it’s actually more like the system used in later 5-star games like People’s General).
None of which is bad. This is actually a better tactical setup than PG had, as far as I’m concerned. It’s a lot more interesting, with more viable options each turn, than what you would get in PG. There are real decisions to be made about whether to surround an enemy unit or not (and how much to surround them) – trading off flanking bonuses for the ability to move after shooting and/or the ability to attack multiple targets. Artillery is also more interesting this time around, being a true support weapon.
I’m through just the first few missions, but so far my impressions are very positive. The tactical options seem great, it looks great, the scenarios are good so far. Shame about having your cousin to the voiceovers, but other than that, no complaints!