Deus Ex: Human Revolution is, again, a huge mix of play styles and mechanics. In addition to combat and stealth options, there are also social and hacking elements at play and choosing the right Augments (player abilities) go a long way towards defining your experience.
You'll have to decide early on how you want to proceed through Human Revolution. You can choose between difficulty levels, though even on the easiest setting, you need to figure out what sort of character you want. Are you a stealthy character, or more of a run and gunner? Either option works and comes with its own inherent difficulties.
Gunplay is tight, though you run the risk of running out of ammo or being overwhelmed by guards. It is possible to shoot your way out of every situation, though you can't charge through with reckless abandon. Hitting the shoulder button while next to cover drops you into cover. From here, you can engage in cover-based gunplay, though the button configuration will take some adjustment. The two shoulder buttons are assigned to firing your weapon and dropping in-and-out of cover, so trying to iron sight enemies (assigned to a click of the right stick) is tricky. Dropping out of cover to quickly pop off a few shots will take practice.
You can bypass a lot of tough areas using stealth, though you aren't as resistant to damage and will need patience. Although I'm usually a more aggressive player, I ended up sticking more towards stealth. Sneaking around and finding alternate paths is incredibly satisfying and reminiscent of the Thief series. It requires a lot of patience and planning, but when it works, it is a lot of fun.
The key problem with stealth is that enemies are sometimes a little too perceptive and will spot you even when they shouldn't be able to. This was especially problematic while trying to hack consoles. Hacking is a cool mini-game where you find the right file path to the CPU's core. Thing is, some files will trigger alarms while others take longer to scan based on your Hacking skill. Even at a high skill, this takes a while and I was sometimes spotted during the game - even when crouched behind the terminal. Several times, this disrupted the bonus of shutting down cameras or reprogramming turrets/ robots - both big parts of stealthy play.
The social aspects are fun and could teach Mass Effect a thing or two about engaging players with conversations. During conversations you have a branching dialogue tree, though you can purchase Augments that further enhance the trees by showing personality read-outs. These offer new pieces of dialogue and new quest-completing options.
Deus Ex: Human Revolution has a few rough patches, but is an otherwise remarkable game.