The movie is surprisingly accurate considering that it was made during the war, although around that time it was pretty obvious that the Japanese were most decidedly on the backfoot in the Pacific. Indeed, volunteers were selected for the raid, indeed, it was to hit Tokyo and Nagoya, indeed, it was spotted by a Japanese patrol boat, and the raid did a rather inconsequential amount of damage (aka the "do little" raid), and lastly the pilots were to attempt to fly to China, where a few of them managed to make it into Chinese lines.

What should be noted are the consequences of the raid that the movie rather glossed over: namely, the Japanese sent a large force into the area to neutralize further such air raids, in what was known as the Zhejiang/Jiangxi Operation. In the course of this operation, which had the primary objective of seizing airfields in the area, many Chinese civilians died.

There's also a general suggestion that the Doolittle raid caused the Japanese to make a hasty decision to attack Midway. In fact, the decision to attack Midway had been made two days in advance of the raid, and in fact the raid ended up delaying the Aleutian Operation as the light carrier Ryuho had been damaged and would be unable to participate.

I think of interest was notably this line from the movie, where one of the men states "You know, I don't hate Japs yet. It's a funny thing, I don't like 'em, but don't hate 'em." Something very unusual to hear about your enemy when you're fighting a war, and making a film for arguably propaganda purposes.