LG has a feature where the TV will auto-dim when the screen is dark. This means l can't see anything in the game when it's dark (which, from the demo is a lot). This has only been a minor nuisance before but this sucks.
My cousin has this problem on her TV and the solution she found was to turn off the "energy saver?" (can't remember what it's actually called) function. Like you, she had no option to turn off the auto-dimming but turning off the energy saving thing did it.
"Uh, 'video game' you say? Well golly gee, you mighty spacemen of the future will have to show me how it works." - Fry