Corrected entry: The Bio-Dome itself is supposed to be airtight, yet if you look at the bottom of the entrance door you can see light escaping through it.
Corrected entry: Watch Bud's pants when he and Doyle are putting up the fly paper. They are pants in the beginning but in the scene where they are showing Romulus their "suprise", they turn in to shorts.
Corrected entry: In the Scene where Bud and Doyle find the key, they are in the Desert Section of the bio-dome. In the scene where they are letting people into the Dome for their party it is in the Jungle section of the Dome. If you look through out the movie at the window there are no other key slots, so it couldn't have been a different window.