Beat on Hard "Give me Deux Ex". I had a bit of trouble at first as I was getting used to the mechanics and had to do a registry edit to turn off mouse acceleration. I had to install a noclip mod (which also required setting up an xbox 360 controller on my PC) to fix a side quest early on where a guy I had to take out spawned up in the sky. I wasted way too much time hoarding loot and running guns 1 at a time to the store to make money, which I in no way needed. I made sure to go everywhere, loot everything, hack everything (plus get as many data caches as possible), and take out every threat; all to maximize my gain of xp and loot. This in turn was the part about the game that I disliked the most; breaking sensible play in favor of game mechanic rewards.
I tend not to like cover based shooting, so I more often than not went around in free aim. Often I would go into cover just to see where the enemies were, then exit cover and pop up (or out) to shoot from first person view. I found the 10mm pistol to be the best weapon. It was easy to aim in first person view and the armor penetration mod made it the weapon of choice for armored enemies and bosses. The combat rifle was my 2nd most used weapon, and I focused my upgrades on it. Good for taking out unaware enemies with headshots, though I found the iron sights to be somewhat awkward. Really disappointed that there was no scope upgrade, though the laser sight helps a little bit. I started off with a double barrel shotgun and silenced sniper rifle. The shotgun was garbage and I literally had to save scum to get any kills with it; the regular shotgun is not much better. I used the sniper rifle as a crutch in the first mission to thin out the enemies, though I rarely used it afterwards. It was good for taking out snipers but I found it unreliable for taking out armored enemies in a single shot; I think I prefer the loud sniper rifle. My most used weapons though were the tranq gun and melee. I went non-lethal for most of the game simply because it was easier and more effective. I did enjoy the tactical aspect of hiding the unconscious so their buddies would not wake them. There were only 2 times where I deliberately avoided (read save scummed) killing anyone, and that was the police station (for obvious reasons), and some body guards that I could entirely sneak past (I just took them out for xp). I felt slightly guilty for killing most of the enemies in the last level, but I wanted to because it was fun.
I focused my augmentations on carrying capacity and hacking (just the ability to hack all levels), to maximize xp and loot gain. Then I got see through walls, though it was not quite as useful as the previous games due to the radar. Next I went for damage reduction, gas immunity and jumping. After a number of fall related deaths, I got fall protection. Then I went for turret hacking, strength, punch through walls, recoil reduction and multi target melee. Eventually I just started getting minor upgrades because I had so much xp that I did not know what to do with it. I never bothered to use the typhoon or stealth features. Turret hacking + str to carry around the turret was an awesome combo; I was even able to get a turret into a boss fight and you better believe I abused the hell out of that.
At the end I chose the purity ending because it was the truth, though both strict regulation and unhindered progress have positive aspects to them. My overall opinion on augmentation is that improvement should be pursued but the actual improvements used should be strictly regulated so as not to create class struggle between those who have augments and those who do not, so maybe I chose the wrong ending.
Next I played The Missing Link dlc and found it to have the same high quality as the base game. Disappointed by the end fight though because it was not a structured one on one boss fight. The "boss" ending up getting killed by his own robot after I snuck past it, melee tookdown the snipers, hacked the robot then fired an unsilenced shot to attract the enemies close enough to the robot.
One of the best games I have ever played, despite some bugs and design flaws. Loved the story, characters and immersive detailed world building. The game mechanics and progression system lend well to player made maps, so I will have to check that out at some point.