There's a Deus Ex retrospective on one of the Gamasutra blogs; here's a snip that rang true for me:
More information.Despite its faults (the pulverisingly unforgiving difficulty for new players, clunky graphics even for turn of the millennium gaming and repetition throughout the middle act), the most depressing thing about Deus Ex is how little influence it has had over subsequent gaming culture. As the games industry grew and became more mainstream, much of the reckless experimentation that produced many of the greatest games of the late '90s (and a few of the worst: take a bow, Jurassic Park: Trespasser) was left behind in favour of a formula mentality. Derived in thought and execution from the sensibilities of the Hollywood blockbuster, for all its financial success the gaming landscape was made a less exciting place to play. Even Deus Ex's maligned sequel Invisible War dumbed down the RPG elements to make them more palatable, while the trailer for the series' third entry ignores real gameplay in favour of pre-rendered spectacle.