Blender game engine would not be ideal for 2d games. Ive used it a lot.
prosIt is really good for people who do not want to learn too many programming languages, and can be completely programmed with "logic bricks".
If Nifflas can learn how use the 3d modeling part of blender, intergrating it into a game would be extremely easy. Just put all the parts together, assign physics and controls, and the basic game is done!
It uses Bullet Physics, so making a game with physics is very easy.
Its functionality can be extended with python scripting.
consBecause blender was originally made for 3d modelling, the blender game engine isn't as usable as it could be.
An example is that making a particle system in modeling is different from making a particle system in game engine.
Also, textures do not work the same in game engine mode than they do when rendered.
Other
It has many different Python script extensions, but not enough to cause problems. Most of these are Import or Export scripts, but some are useful, such as:
City generator
Nut and bolt creator
tree generator
and a few other useful ones.
These scripts are NOT compiled, just .py, so you can edit the scripts and add your own parts to it.
it is pretty powerful, but i am not entirely sure how stable it is.
It is good to get into, because there is a script to export to flash 3d.
As someone said, it has a very steep learning curve, it took me ages to figure most of the stuff I know out.
Overall, I recommend it, as it is simple to make a 3d game, and it can then be exported to a runtime.
Oh yes, its multiplatform.
Linux
Windows
Mac
Solaris
Irix
On an entirely different note, good luck with finding a good game development platform.
I have used blender extensively
EDIT: here is a really good video to show the large features of it:
http://www.youtube.com/watch?v=pc9JWYuUa2oand here is a full game made in blender
http://www.youtube.com/watch?v=Canbxj0RBTk