i think what makes the original deus ex so timeless is its unrivalled dedication to foresight. you've played games like it right? where a dishonored or two show the very clear "hey here's an alternate choice wink wink" routes you can take? the sequels do this even, all but plastering vents and computers with flags and a bullhorn.
deus ex stands out not because of those options, but because it anticipates everything. its ridiculously difficult to sequence-break, glitch or cheat without something in the game acknowledging it. the developers anticipated possibilities that the player could invent, not just what their design intentionally offers. its a specific ethos i seldom see implemented to such a degree today, if at all frankly, and why people keep holding it up as a gold standard. i cant blame them, nobody did it quite like ion storm.
edit: i like to phrase it as most games being clever with its multiple choices, whereas deus ex seems to know how you'll play better than yourself
