The short running time is countered slightly by the inclusion of achievements, which reward you for reaching certain milestones. Defeating 15 crooks lands you a 'Vigilante' badge, for example. Completists will want to replay each level to reach each of these targets, so such people can discard criticism of the game's brevity to a certain extent.
Unfortunately, replaying the game will only emphasize the other issue of repetitiveness. Perhaps some smaller but more free-roaming and combat orientated levels could have been thrown into the mix to keep things fresh. Alternatively, a level where Hancock flies off to Tobago on a jolly would have been fun. But perhaps that's just me.
Regardless of these issues, the Hancock formula makes for a neat twist on the usual superhero fare. Ultimately it's a worthy and well thought-out accompaniment to a summer blockbuster. And that's not something that can be said too often.