Curtis Jackson, also known as 50 Cent (what his British name is depends on the exchange rate that day; today it's 31 Pence), is not really somebody that I would associate with the world of movie-making. At least, not until I saw Gun and became aware of his previous output (you might be able to tell that I don't pay much attention to the careers of rappers).
Gun is a film where the subject is what it says on the tin. Gunrunner Rich Taylor (50 Cent) is targeted by the Detroit Police force to stop rapidly raising crime rates (I'm on their side here and I feel most viewers would be too). He bumps into his old friend Angel (played by Val Kilmer, who has changed a lot since Batman Forever and Top Gun), who saves his life in a gun exchange with Machete's Danny Trejo. Things heat up as the gun squad tries to do what it needs to in order to take Taylor down. The film takes a fairly predictable course for the rest of it.
50 was prompted to write this film by the interesting nugget of information that sales of guns have gone up by 125% in a recession (a nugget so interesting that it gets used in an in-movie radio news bulletin). It is an interesting subject, and it does serve to show the kind of difficulties that a police squad would have in taking down gunrunners.
However, where the problem lies is the execution. They give the protagonist Rich a Batman-like backstory that is kind of confusing, given what he actually does because of this backstory. I don't know if they were intending to go for this, or if Cent insisted on it (after all, he did write this) but there is a totally gratuitous sex scene with 50 that seemed to come out of nowhere, which could potentially serve to glamorise the gun-running life. Not only is it the kind of scene you do not want on your television in case anybody walks in (so you spend more thought on wishing it would hurry up than entertaining any thoughts of arousal or appreciation), but it was also rather more Naked 50-Cent Ass than I wanted to see. If he wanted to be a bit cheeky (if you'll pardon the pun), he could've put in a bit of appropriate music for the sex scene, Kiss' "Love Gun".