The film remains sincere no matter how silly it gets, and the R-rated gore is ridiculous. Just when you think the movie is following a certain course, something happens, and it follows the gag way too far. The Hollywood spoof is aware, but not so inside that it would lose people.
Now, Tropic Thunder is good and entertaining, but it's not totally consistent. It's hit and miss, but the hits are big enough. You recognize that there are going to be some obvious groaners or just lines that go flat, but hey, they need to forward the plot sometime.
The premise itself is cute, but not brilliant. We get it, they're still acting but it's real. At its best, Tropic Thunder carries that to the extreme. Sometimes it just coasts through though.
Still, the film achieves the biggest fete in Hollywood: undoing Tom Cruise's last three years. He goes for the buffoonery in the most lovable, self-deprecating performance possible without being self-congratulatory. Bravo, Mr. Cruise. I still believe in chemical imbalances though.
They should keep up the bloody violence but they don't. Robert Downey Jr. inventing Hollywood catch phrases is pretty awesome. So it's good entertainment. There's probably something for everyone, which means no one person will get everything, but I'm not selfish.