I found this game engine and I tested out some stuff on it. It has a very good potential.

http://www.crystalspace3d.org

Features:
AWS-window system with skin support
3d shader support
3ds and Blender level format converter
3d Alpha
lightmaps
animation
sound support for *.wav(SFX) and *.ogg(BGM)
3d sound effects
Particle system!

If anybody has ever used this before: How can you put picture buttons and (Black) text for dialog and such. I can't find the parameter in the layout(XML), sheme(XML), or even the source for the demo. I'm also trying to change the shader for "cell shading" more specifically "toon shading"(no ambiance, but no dark outline).