TOO MUCH TIME ON PREPARING FOR THE HUNGER GAMES
I realize that the preparation for the Hunger Games takes a large chunk of the book, and the movie decides to do the same. Unfortunately, director Gary Ross takes these scenes and turns them into long, dry scenes of preparation in which he completely botches the "Girl On Fire" scene in a poorly staged reveal where she looks like a Girl on Sterno, turns the preparation into the world's most boring gymnastics compatition, and gives us little sense of any of the characters except Peeta and Katniss. What was engaging on the page falls flat when staged as literally as possible.
POORLY STAGED ACTION
A lot of people said the book's violence couldn't be filmed and get a PG-13 rating. Bull. Plenty of movies full of gratuitous violence, including the very first PG-13 movie, Red Dawn, come to mind. Unfortunately, Gary Ross seems to have taken these warnings to heart and decided to take the book's brutal games and turn them into an MTV video with all the emotional weight of a round of Call of Duty. The game's opening scene in which competitors scramble for supplies goes by in a blur in which we really have no idea who is fighting, or even what's really happening. We know people die, but it's less brutal than it is a way of making sure that there are fewer competitors left for the plot to deal with. Even the final battle on top of the cornucopia is a jumble, with the horrifying final attack by beasts crafted to look like the fallen competitors turned into a blurry scramble away from some generic looking panthers.
NO SUSPENSE, IDENTIFIABLE VILLAINS, OR THREATS
There are three books, so even those who have never read the first book have a pretty good idea that Katniss survives. But so what? We know Harry Potter, Indiana Jones, James Bond, and plenty of other heroes will be there at the end, but in a decent action flick, we fear for their safety and are left wondering how they're going to get out of the next scrape.
In the Hunger Games, we have no sense that Katniss is ever in any real danger. The threats are all faceless (the other competitors), or so distant from the action and Katniss (the President and Seneca) that there isn't any real dramatic connection among any of them. And even when she does get into a scrape, the way out always seems too easily won, either by a well timed parachute, or a competitor stepping in to help.