It's not awful, and there are some laughs, but overall…eh.
It is, if you didn't know, a remake of the 40-year-old TV spy parody Get Smart, with Steve Carell as Maxwell Smart, Anne Hathaway as Agent 99. They work for the super-secret agency CONTROL; Alan Arkin plays their Chief. They're up against their nemesis agency KAOS, as usual, with Terence Stamp playing arch-villain Siegfried.
The movie ritually recycles many of the old show's gimmicks and catchphrases: "Sorry about that, Chief"; "Would you believe…"; the shoe phone; the Cone of Silence; and many, many more. The screenwriters appear to have been working off a checklist, which is fine, but makes the whole thing scream "this is a contrived remake made solely for crass commercial purposes" just a bit louder.
Anti-spoiler: Agent 99 makes numerous references to her mother, and the movie seems to be setting up for a Barbara Feldon cameo. (Ms. Feldon, youngsters, played the original 99, and she was awesome.) Doesn't happen, though. Instead we have to be satisfied with a brief appearance by Bernie Kopell, the original Siegfried. There are a couple other cameos as well, including Bill Murray, who should have been given something, well, funnier.
Consumer note: the DVD has a gimmick that allows you to view alternate line readings and deleted scenes within the movie itself. Don't bother; this makes the movie much longer without being any funnier.
What's next? The Man from U.N.C.L.E. movie? Or perhaps Gomer Pyle, USMC.