After watching the first 10min I seriously had to do some research, if this was a real Marvel production. In my opinion this is a "C-Class animated movie" at best. Definitely not what I expected from something with a Marvel label.
The title should have been "Iron Man & Shrek in an Hulk costume: Heroes United", and I would have had the adequate expectations for this. In my opinion this green mixture between Oprah and Jim Carrey is just ridiculous for an Hulk interpretation. I wonder if any one who was in charge of this ever saw a Hulk comic. For me it looks like they got confused and mixed up Shrek and Hulk.
The story is weak, quite a lot of inconsistencies and gets more ludicrous by the minute. I'm pretty disappointed, I did expect something more along the lines with "Hulk vs. Thor" or "Hulk vs. Wolverine".