During the Mars-flight, the way the spacecraft uses the rocket thrusters is unrealistic. For example when they are nearing Mars, they should be using the rockets against their movement, to slow down the speed. But in the movie they are using the rockets towards Mars.
Co-star Michael Madsen, whom also appeared in the first film, has stated his distaste with this sequel, especially in comparison to the original. He once referred to it in an interview as a "crock of s***."