I wanted to try if a 3D mode would be cool for the game. I played during 2 days with Irrlicht and decided to implement it for the game (as another View, which allows me to use the 2D or 3D view anytime I want). Irrlicht is maybe not the best (I don't like how they code and there are many mistakes, like the returning a full object instead of a const ref some times... and missing optimization like using a list instead of a vector is sometime useless). I'll move to another engine if I need it.