Minority Report has a great concept as a film and with all the inspirational pre-crime and pre-cogs stuff in it it certainly has many nice ideas. The problem here seems to be that Spielberg has actually too many ideas to work with and way too many sideplots and elements than he can handle. End result is a great looking but flawed science fiction noir with occasional flashes of brilliance.
Those brilliant moments, which are mostly well made action set pieces, are mostly overshadowed by silly and banal comedic moments and messy screenplay that loses its focus too many times. While Minority report might look and sound great it still is not even nearly on the same level with his best films like A.I. or even with War of the Worlds, which was much more focused as a film.
There are also moments in Minority Report that feel unnecessarily elongated when it comes to a plot and the final act feels way too overlong for its own good. Spielberg manages visually to show us fascinating and scary vision of near future with amounts of paranoia and mind control, but he cannot breath real life into his film that would make it fly.
Spielberg proves that he surely can direct a good and entertaining set piece but he also needs a well made sceenplay which writers Jon Cohen and Scott Frank cannot deliver. Minority Report is grim, too complex for its own good and lacks the true spirit of the best films of Spielberg. It does have strenghts but mostly Minority Report is a missed opportunity.