Judging from the screenshots, I think you're using the term "2.5D" wrong... 2.5D is something like Klonoa or Castle of Magic. 3D characters, 3D worlds, but a 2D plane (side-scrolling).
This game you have here is definitely 3D. They are open environments, 3D character freely roaming around a 3D world.
Just thought I'd throw that out there
Unless your character is on a straight fixed path during the game? It doesn't look like that from the screenshots, but I did notice the character is always in the very middle, so maybe I'm presuming wrong
But this looks great. I'll definitely have to check it out