What you see below is a screenshot from my WIP RPG tech demo.  The graphics may appear to be retro, but this is a stylistic choice, since they're attractive, readily available, and relatively easy to add on to.  The engine itself is capable of running at an arbitrary resolution, with arbitrary tile sizes.  It uses OpenGL for rendering, so it can also display 3D objects and cool particle effects without a whole lot of extra effort.  That being said, it is fundamentally a 2D engine, so building a 3D game out of it wouldn't be a particularly good choice. :)

The engine itself is written in C++ and built on top of the Qt GUI toolkit, which has a lot of cool functionality that can be leveraged for game creation, such as XML parsing, integrated scripting, database integration, and (of course) GUI widgets, which can be rendered with transparency on an OpenGL surface.  It comes up a little short on audio support, but it coexists with SDL_mixer with no complaints.

This project makes use of the Tiny Town tileset by Surt and Antifarea's collection of 16x18 character sprites.

I'll try and post a video some time soon. :)