Right, I liked the first one well enough so I bought the expansion. Or the sequel as they would say.
So the mechanics really haven't changed at all since the first game. You still draw 5 cards a turn. You still beat up/buy cards with the power in your hand and make your deck that way. You still get to play as superheroes with special unique abilities. That's good in a way I guess. They're keeping it simple, which was one of the draws of the original game. The only things new are the cards. Even the staples like punch, kick, vulnerability and weaknesses have gotten new art.
Like before, there are certain super-hero cards that stand out as being really good and others that just seem like crap. For example, Hawkman is infinitely better than Batgirl. There's just no question about it. I literally have no idea how Batgirl's ability is good in anything other than early game. Then there's the weird cards like Red Tornado; whose ability turned out pretty useful later on and Shazam, the more expensive version of Riddler. Again, I think the take-away moral is Batgirl sucks in this.
Now I've played through this game a few times by now since I got it. And by a few times, I mean a lot. And by a lot, I mean more than 10. And I'll say this much. The tone of the game has changed a LOT since the first game. In the first game, there were less card combos that could be pulled off. In general, most cards were pretty good by themselves with the exception of the Riddler, Two-face and in general, most villains. They sucked. In this game though, the overall power level of most cards; except villains, seem to have gone down while the combo-bility of the cards seem to have gone way up.
Just saying for some of the cheaper and easier to pull off combos, there is Superboy and Starbolt. Superboy brings back Starbolt to your hand as well as giving you 1 power. Starbolt gives you 2 + x power where x = the number of superpower cards in your discard pile. Usually, I find this is safely between 4-5 power in total. That's usually 5 power for 2 cards, which isn't bad, considering one of those cards is essentially free cause you put it into your hand from discard pile.
Then there's the Demon Etrigan and Jason Blood, the recursive loop of +3-4 power. Etrigan puts Blood on top of the deck so that when you play him next, you can put Etrigan on top of the deck so that your next hand gets Blood again. Keep repeating until your fellow players beat you physically for wasting their time.
And then there are some cards that are just sick. Like Sciencell. This is just an insanely insanely sick card. It has 2 power and it's VP total = the number of different villains in your deck. In general, whoever has gotten this has won considering the cards can sometimes be 10 VP by themselves since super villains count as well. I mean, this card is like Suicide Squad from the original DCDBG on steroids since it doesn't key off other similar named cards.
As before, DCDBG:HU is still a fun game except games have gotten a lot more brutal now. The power curves up much faster than before due to the number of combos in the game, which means you're defeating villains that much faster now. As I said before about the original, this is a fun game to play when you're playing with friends and just want to have fun. It is by no means a balanced or competitive game.