Went at about 3 PM, picked up my VC4 preorder at the Canadian version of GameStop...
Basically played it for 9 hours straight. I think I've barely dented the game's content. My favorite characters are Kai, the main sniper lady, and a scout named Rosetta who's just the sweetest thing ever. They use they/them pronouns, but from the layers of it being a translation of a Japanese game, I think Rosetta's a transwoman...
Anyway,
Gameplay is basically an improved version of VC1. You have your standard Scouts, Shocktroopers, yadayada, but now you have grenadiers that excel at taking out bunched up groups of infantry and slow down tanks and soldiers with suppressive mortar fire. You also get an APC like ten battles in that lets you transport up to two units at a time. Oh, speaking of vehicles, instead of them costing two CP to use, they cost one now and all their ammo is limited instead of just the mortars like in VC1. I think that's a much better change, especially when you don't have a Lancer hero unit any more.
Not far enough into the story to make any calls about it yet, but it seems like typical anime melodrama so far. Obvious romantic pairings almost immediately, which I'm not too sold on yet. I thought maybe everyone's favorite imperial general, Radi Jaegar came back, but it's just some guy that looks similar. I know that someone in the main good guy cast is likely to be a Valkyria, because that's how literally every VC game has worked since the series started, but I have no clues yet to who that might be...
That's about it for now. I definitely enjoy the game, since it really is just an upgraded VC1 (which is what everyone wanted instead of the handheld VC2 and VC3)