The story of chasing down renegade replicants who want to extend their lifespans, and who do so by terrorizing Tyrell employees, is just too similar to the movie. Roy is almost a carbon copy of the Deckard character, even in how the game suggests that Roy is a Replicant. Clovis is basically the Roy Batty character in the way he dresses and quotes literature. Plus all the movie locations you visit, and the movie characters you talk to... there's just too much overlap with the movie. I get that they wanted to do some fanservice, but its too much at times. I almost expected characters like Chew or Sebastian to ask Roy "Haven't I met you before? You're also chasing a group of replicants who want to extend their lifespans?"

The game is a tribute to the movie and the book and has a lot of material that is mostly fan service.
Clovis is largely a copy of Roy Batty (although he does have a somewhat expanded plan in comparison), the start sequence in Dektora's dressing room mirrors the approach of Deckard's to Zhora.

I still would maintain that the game gives you far more to do in this world, in spite of the overlaps. And the themes that it introduces or re-creates from the book are quite welcome -- the importance of animal life and McCoy's love for Maggie, the sequence near the end of Act 3 and (at least) the idea behind the setup and events in Act 4, the "failed" Replicants, the CARS movement, the competitiveness among Blade Runners, the alternate endings (...).

The story will also adjust (enough to matter) for McCoy to be whatever the player will play him as. He can be a hardcore Blade Runner, a Replicant or Replicant sympathizer, or a huge jerk.

I maybe forgetting the movie but I think the game does do what you mention with a few characters; on Animoid Row, the Tyrell meeting and Yukon hotel characters will mention that another Blade Runner was asking around or investigating a crime scene and McCoy can pick up a path of clues that he will eventually admit is separate from his investigation.

I assume the game designers, besides providing fan service, wanted to show off the ability to render locations from the movie in video game format.

I do think it'd be interesting if another game was ever made to have either a plot with a very highly-placed Replicant who has convinced humans he/she is one of them, or have a bunch of unconnected assignments mostly just involving one or two Replicants each (like one assignment could be to locate an especially dangerous Replicant whose cover is completely blown and who is hiding out in some remote, foreboding place that isn't a sewer.)

Hell, you could even have a game where you play as a Replicant who has managed to get onto earth. Not only would you be hunted by one or more Blade Runners (and killing one would presumably intensify the search for you), but you'd have to determine how much you wish to "integrate" into human society or simply stay away from people, whether to try finding other Replicants to team up with, whether to try escaping the planet, etc.

Story of movie and game run simultaneously, sometimes Roy is first on some place, sometimes Deckard (although he is not visible in game, but there is always some note). According to my opinion game is based on movie atmosphere, but makes everything better. For example in movie is absolutely great speech (probably reason why many people consider it as a cult movie), but rest is only mediocre (basically what you see and what you hear does not match). In game you are "nobody", but you can do some moral decision and change things (to some extent) with same atmosphere and time to relax (famous balcony scene).Unlike movie game has flow, it is hard to stuck, but if you do not pay attention you could miss something what limit your future possibilities, thus to make more play through make sense, not only because replicants are not always same people, but to see different endings.

Moreover I am looking forward to "restoration project", because this game is much better than movie in vanilla version... ...with more content (which was originally in plan) it will rock! ;)