Movie is real, production has been done since October.
Not 100% sure on the poster, but as far as I know it's fake. If it wasn't, it's very old.
I suggest reading the Wikipedia for more information:
Some other random tid-bits I remember from the news videos online:
- The Eggman costume is all black and he isn't egg shaped.
- They're going with a Classic Sonic design with changes to make him fit into the real world (think Detective Pikachu).
- There's a chase scene that was filmed on a highway
- There's a suburban town in the film called Green Hills
Overall, things aren't looking good for it, and I'm a Sonic fan.
Yes, there's a chance this could turn out to be wonderfully weird like Detective Pikachu, but unlike that film there isn't much evidence to show that the Sonic movie is being made by people with an understanding and love of Sonic. The whole thing screams corporate cash-grab.
I'm gonna love Ben Schwartz as Sonic, though.
If you ask me, they should have made it completely animated. And in a perfect world, it would have been written by Ian Flynn from the comics, one of the very few quality media this franchise has left.