I was skimming through Behance a couple of days ago looking for gaming related design works and stumbled across a group of posters created by Rachel Morris for NYU Game Center. Not that I have a breadth of experience to start critiquing here but I really enjoy the subtle use of basic colors and shapes in these without the need for either a) over-the-top coloration and/or b) the retro look that so much gaming related art seems to hang on to.
Source: Rachel Morris