Not as Bad as They Say It Is
You play as Flik is a linear challenge of over 10 levels plus bosses. You start on the training level, which is optional, all to the assistance of the elder ant (I forgot his name, it's been a long time since I saw the film). Then you are going through Ant Island, the tunnels, then you fight the pet of the grasshoppers, Thumper (he's psycho). Then you avoid a monsterous bird flying through the cliffside and you go through the canyon, defeat the bird, reach the city, and then you keep going and following the story of the movie. While told a bit inacurrately.
Flik's main defense is throwing berries (how can those hurt?), the red ones are weak, the blue are tougher, the green and purple track down the foes destory them, and the gold one thoroughly damages them. The levels do get challenging, you can also look for the letters F, L, I, K and spell out the name of our main character. You also can collect 50 pieces of grains. The sound is okay, an okay music score that fits in with the film, plus the speech is okay, Flik talking too much can get annoying, the graphics are kind of okay, nothing superior, not as good looking as the film (which was a techinacl triumph for Pixar). The final levels get tougher and a little more fun as you play through them. You aren't offered too much health either.
Overall, if you are a hardcore Pixar fanatic, I suggest renting it, but if you are looking for a linear action/adventure game, I wouldn't try it because it seems to be underrated. The Toy Story game is better though.