Kevin Feige, the head of Marvel Studios, has been doing a lot of promotional interviews recently. Interestingly, he noted that, unlike the DC Comics Cinema Universe, Marvel films are never going to go the route of dark, ominous features. Feige noted the escapist fun and humorous approach Marvel films are known for should not be deviated from. He is right. Other than the Daredevil series on Netflix, it is not very wise to go with the gritty approach.
Marvel Comics, throughout the bulk of their publishing history, opted for fun entertainment. Yes, the Marvel Magazines of the 1970’s were known for their adult themes. The violent approach of Frank Miller’s Daredevil in the 1980’s saved the comic from cancellation. The R-rated Marvel Max line of books sold well in the 2000’s. Overall though, Marvel books are known for their fun, upbeat nature. Mikal Watts suggest that the films are pretty much the same and, considering the billions upon billions of dollars they earn, no one should change what is working.
DC Comics went in the direction of grittier, more mature stories because it had to. Batman simply was not drawing the younger demographic of readers so Batman tales became more realistic and adult-themed. This helped the book thrive massively. Spider-Man, however, would never, ever work with this style of writing. The same could be said of any number of Marvel titles.
Leave that stuff to the DC producers, instead.