What's the second one? There is only one with the blue aliens.
The second one is the live-action adaptation of "Avatar: The Last Airbender", "The Last Airbender", referred to as "Avatar (the movie)" (or similar) in some circles. It changes between 'blue alien' movie and ATLA movie depending on context, hence the asking. One review of the latter just put me off watching it at all. It appears to be so bad that you don't even know it exists at all.
I don't know if the ATLA movie had a 3D release, per se, but it's not a dumb assumption to make; 3D was sort of The Big Thing for a while, no?
That's... a common in-joke for ATLA fans, pretending the movie doesn't exist. Looks like you missed it.
And yes it's shit. Read this article.
I like to think of myself as ('like to' being the key phrase) being decent at in-jokes, assuming I actually know about it. I walked straight into that one; tripping and falling down a flight of stairs, presumably. Detecting joke
questions is where I tend to fail, seemingly; I've missed the point of a lot of joke questions, and specifically only questions. Joke-anything else appears to be interpreted correctly (for some arbitrary measure of "correct"), but questions trigger an urge to answer, bypassing joke detection entirely.
Not my finest work, but a lot of things are, by definition, not my finest work.