Good? It is definitely a good game. Great? Well, no. DE:HR fails to do what it wanted to do and even though it is a beautiful looking game, there's just too much that was promised that went undelivered to really call it great.
The game that we were supposed to have was an action RPG, but what we got instead was a cover-based shooter with stealth and RPG elements. The biggest problem with the game IMHO is that they didn't explore enough ideas for mechanical augmentations and as a result, specialisation is damn near impossible. Every playthrough I end up with the same damn sort of character I had on the last run I did and it really does get repetitive to know that you're just retreading old ground from a game which promised nothing but choice and paths to follow with a lot of replayability. And it's not like implementing more and better augmentations would have been very hard. Watch:
I know that digital is taking over everything, but why aren't there any manual locks at all in the game? Having to steal or find lost keys if you didn't have an appropriate lock-picking augmentation in your fingers would already give a lot more opportunity for character customisation. How about a badass jetboot augmentation for making tricky jumps over long distances? That way, you could implement rooftop routes to your objectives. What about that social upgrade? Upgrade it once and you're a completely suave and smooth talker that can convince almost anyone of anything. Why not make that a bit harder to upgrade so social boss fights become less of an annoyance at spending 2 measly Praxis Points and become more difficult and complex? On second thought, why can't you just convince guards to let you in places with your social augs? And what about the augmentations from the original Deus Ex you could easily implement? The ability to make rockets explode when they're fired at you would make for some great laughs in this game. Oh wait, there are no rocket-firing enemies in this game. Which actually brings up my next problem...
Enemies are incredibly bland and predictable. On every playthrough, I encounter 3 varieties: people with guns, people that go invisible and also have guns and people with bigger guns. There's no difference in tactics between removing the people with guns and the people that are invisible and also have guns. Why aren't there enemies with rocket launchers? Flamethrowers? Tranquilizers? Where's the variety that the original Deus Ex had in its enemies to take down?
It tries its best, bless its heart, but it's just missing too much to be called great. Not enough paths to take in a level, not enough augmentations, not enough levels, and not enough story.