Despite its low fidelity and awkward character AI, I have never played a game in which the player's presence in a virtual world feels this authentic. Hub areas such as Hell's Kitchen and Hong Kong are rich microcosms. These places may seem small in comparison to open-world games, but they are dense with detail in the form of secrets, newspapers and data cubes to discover and study, as well as inhabitants that philosophise, ask for your help, try to manipulate you, and take note of your actions.

The game's unmatched reactivity makes these characters seem real. Rather than ignoring your agency until some Big Binary Plot Decision like most games, the denizens of Deus Ex will react to your most minute actions and comment on the places you visited, the problems you solved and the manner in which you solved them, the people you met, killed, or let live.

The scale and complexity of the main missions' maps is often mind-boggling; the plethora of ways to move through them almost overwhelming. You can blow up a door and go in, guns blazing; pick a lock and sneak inside; stack crates or use your jump augmentation to reach a high window or roof; crawl through twisting systems of vents; hack security panels to turn the enemy's robots against them, etc.

Affordances depend on your character build and inventory. Skill points are awarded for completing objectives or finding secrets and can be invested in weapon handling, hacking, lock-picking, swimming, and more. Augmentation canisters target specific body parts and offer a binary choice: do you want to move quietly or quicker? Do you want to hit harder with melee weapons or lift heavy objects? These augmentations can then be levelled up, allowing further specialisation, while weapon mods can add scopes, increase accuracy or reduce recoil.