2D game design

I am aware that this question has been asked repeatedly. I am looking for a solution to make a 2D game using unity. The game uses tiles and sprites for the world and entities (and any in game objects). These are read from an atlas. So far I have written all my code in java (not really relevant to my question), but I have decided to move over to a game engine as I don’t want to deal with all the compatibility problems such as web and iPhone (for video and audio - game logic is obviously not a problem).

Currently, when I load a tile or sprite from my atlas, I do all kinds of transformations with the pixel data (such as color changes, mirroring and rotation). Is it possible to do this with textures on a plane? Or perhaps to an exploit such as this?

I apologize if my question seems vague, but it’s actually very specific (about using GUI or textures). If neither of these are as straightforward or possible please let me know.

Thank you

Have you seen this tutorial? It seems to fit your needs.