hello there,
I was wondering, how can you get graphics like those pics in Unity. Is it specific shaders, low poly models…?
I don’t have too much knowledge at Graphics, shaders, etc.
When I talk about these images I mean the 3D part, because the characters clearly are sprites.
Thanks in advance 
There may not be any real 3D in those scenes at all. Would have to see how the camera moves to be more certain, e.g. do you ever see objects from a different angle?
If you wanted to do it in 3D then yes its a combination of models, textures shaders, along with using really basic rotation of objects in order to look like the old sprite way of doing things. Im not sure quite how many people have taken this approach though, since its probably way easier to create the low-res sprite look by actually using sprites. Some sorts of retro-look are fairly easy to achieve with modern 3D, but perhaps the examples you give are a bit too retro for 3D models to be the best approach. Taking advantage of Unity’s awareness of 3D space, but using 2D billboards within this space instead of proper 3D models, might be the right balance for this case.
But I am very far from being an expert on these matters, I just replied because nobody else had.
Yea, I think this is 2D pixel art. Sometimes they combine a 2D background (wrapped on a plane and 2d or 2d characters.
If you want this look, you could make a bunch of choppy, pixlated art in photoshop, then wrap it on a plane, and then build some simple houses on top. Basically you need to make some custom shaders.
Well the artists did their jobs well, because these are screens from Pokemon Black/White on DS. The environments in the game are all full perspective 3d.