We have been working on Facewound for about 12 months now. Our idea
was to utilize 3D hardware ina 2D game - which I think we have done.
The engine is a simple 2D tilemap engine - with 'props' that can
either be solid, in the foreground or in the background. It also
features lens flares, lens glows, parallax props, realistic water,
rotating props, additive blending props, particle spawners, elevators
and doors. You can add any of these things to a map in the editor. The
engine itself is based around triggers - basically any entity can
trigger another entity. So you can have a door open when you kill an
enemy, then the door opening could trigger another enemy spawning etc.
Most of the advanced features resolve around using pixel shaders. We
use the pixel shaders to create effects such as fully reflective
water, huge explosion shockwaves, bullettime bullet trails(yes, like
the matrix), water drops on the screen (when it's raining) and a fire
heat shimmer effect.
Each map can have it's own post-processing pixel shader too. This is
usully used to give the water a unique colour or a unique reflection
size - or to just make the screen darker/brighter. It can also be used
to add some weird effects (as seen in the shader tutorial here).
We're hoping to have the game finished within the next few months -
after which we will be releasing an SDK for people to make their own
games using the engine.
We have quickly thrown together a pixel shader example movie - which is
shown here : http://www.facewound.com/img/pixelshaders.avi
The official Facewound site is http://www.facewound.com/