How bad does it stink? Well, it definitely stinks worse than the quality of my screenshots.
The camera stinks, even though you can control it manually.
The graphics feel like they wouldn't even test the PlayStation 2's capabilities.
The voice work is flat. When a Sound-alike Robert Downey Jr does better than Don Cheadle, who was ACTUALLY IN THE MOVIE AND IS A MOVIE STAR, you have problems.
Blowing up things is dull. They made blowing up things dull!
So don't buy it, don't rent it, and don't demo it. Well, OK, demo it, because it's free. Then DELETE IT!