Warning: Spoilers abound! Don't read further if you don't want to be spoiled. If you don't care, or you've seen the movie, read on...
I had not and have still not read the short story on which this movie is based, so all impressions given here are based solely on the movie and nothing else.
This is one of those movies that will have you laughing one minute and crying the next. And the end feels like an unexpected punch to the gut. Bring tissues when you see it! Some people have said that "Brokeback Mountain" reminds them of "The Bridges of Madison County"... I might agree with that. I've never seen all of "TBOMC", just a few scenes... I was quite young when it was in theaters and they don't air it on tv very much. But I know my mom liked it. From what I have seen of it, yes, it probably has a similar tone.
Ang Lee did a magnificent job with directing his cast. He really is the master of repression and hidden emotional pain, and it comes through in "Brokeback Mountain." You can see the progression through his movies from "The Wedding Banquet" to "Sense and Sensibility" to all his more recent stuff to this. Heath, Jake, Michelle and Anne are at their very best. The cinematography is indescribably beautiful... as if that would be difficult with the vistas available in Calgary and Montana... I really appreciated the stark contrast between all the natural beauty surrounding the run-down, economically near-dead towns of rural Montana in the 1960s and 70s. And the music just adds so much. Thank you very much Emmylou Harris and Willie Nelson. Thanks to them, Maria and I just cried through the credits... (Zinzi being Zinzi was already out of the theater and looking for the bathroom when the credits started rolling.)
Ennis Del Mar, Heath's character, reminds me of John Wayne or the Marlboro Man in a lot of ways... Doesn't talk much, classic cowboy. He has an interesting way about him when he actually does talk. I don't know if it's just the Montana accent or what, but his jaw doesn't move very much. Ennis also can't dance to save his life and has no rhythm at all. Heath was really making those late-1960s/70s sideburns look really good though! Didn't think that was possible... Ennis is the side of the duo who is full of repression and restraint.
Jake's character, Jack Twist, is a little more open, but comes off as your typical Montana rancher's son turned Texas rodeo cowboy... pretty much what you might expect that to be. Jake said he loved working with the sheep, which they were really herding for real throughout much of the film up and down the mountains in Calgary, Canada, because they were such stupid but lovable animals. He said it was pretty neat how all you had to do was lift up your arms near them and walk toward them, and they'd run away in fear. Made him feel quite powerful. As for the character of Jack, he's a bit more easy-going. He can dance and though he can't sing, he still tries. He doesn't care if he makes a fool of himself, and he doesn't like to be pushed around, although he'll take it to keep the peace. Jack would be the side of the duo who's full of longing.
I really like Ennis and I really like Jack. They both make valid points, and it was unfortunate for them that they had to come about in the 1960s and 70s in the rural West. Even another part of the country at the time would have worked better... or if Ennis' dad wasn't such a psycho and hadn't traumatized him when he was nine, things might have been much easier for him, and therefore for Jack.
Anne's hair as Lureen Twist gets progressively more blonde. She starts with her natural color and by the end is as platinum as Marilyn Monroe. The story moves from 1963 to about 1980, and you can kind of tell how much time has supposedly passed by watching her hair get more blonde, and Jack's mustache get thicker. I'll need to pay better attention to her character the second time around to really figure her out because like Jack says, most of the time we see Lureen, she's just sitting there at her desk, crunching numbers for her father's tractor business, asking why Jack doesn't have Ennis come down to Texas to fish instead of him always having to drive 14 hours to Montana. The only thing that really changes is her hair... until the end... when we actually see some emotion behind the mask of calm indifference.
Michelle's character, Alma Del Mar, moves the story on quite a bit, and she's the strongest female presence on screen... Her life is hard, living with Ennis, with all the secrets and lies between them, and yet, I still don't feel sorry for her because she's better off at the end. She fuels his paranoia a bit, and his carelessness fuels her suspicion... It was a very tense onscreen relationship.
I really liked Ennis and Alma's elder daughter, Alma Junior. She's a lot like her dad, doesn't talk much and knows more than she let's on she knows. And she's very well adjusted despite her surroundings, which surprised me quite a bit. Her relationship of silent understanding with her father is very telling, especially closer to the end of the movie. The part was very well cast as well because not only was the actress very capable, but she also bore a resemblance to Heath. Her eyes and nose are of a similar shape and she has a squarish jaw line... not in an unfeminine way though. She just looked like she could be his daughter were he old enough to have a 20 year old daughter.
You have to pay attention while watching this movie. You might miss something if you close your eyes. A lot of the story is told through looks and body language because the main character, Ennis, talks so little.
I really liked how nature was used in the movie. It was similar to how in "Tristan & Isolde" (the medieval story, not the movie... haven't seen the movie yet.), nature seems to be on the lovers' side, protective and a haven, while society/religion/humanity disapproves. This is also perhaps why the contrast between the town and the mountains is visually emphasized in "Brokeback Mountain" - for the same reason. Ennis and Jack almost always escape into the wilds of Montana for their trysts, and whenever other people come around, that's when bad things happen. In "Tristan & Isolde," the point of nature being on their side is that love is a natural thing, to be protected and celebrated, and that society and religion, which are human constructs, disapproves of their love is unnatural and dangerous... and essentially wrong... This is why "Tristan & Isolde" was so controversial in the 13th century when it was composed. But it wasn't an unusual piece at the time. Much of the romantic literature of the Middle Ages was extremely controversial because it covertly or not-so-covertly criticized the Church and therefore all of Medieval society. So to with "Brokeback."
I recommend the official webpage: http://www.brokebackmountain.com/home.html . The soundtrack plays on every page, and on the soundtrack's own page, you can listen to clips of all the songs. Even if you don't like the movie, or don't want to see it, I recommend the soundtrack. The music is lovely. The site also gives a good impression of what the film looks like.