use what you like better...
gtk is quite easy, openGL is easier, gtk+ is more easy...

you can draw 2d scenes in a 3d api, of course.
If you know the math, skip the 2d part

Funnily enough, most 2D games are actually done in 3D these days - everything''s just aligned to be flat to the camera, so it only looks 2D. The latest versions of OpenGL and DirectX haven''t even bothered with seperate 2D systems - DirectX dropped its one (DirectDraw) two versions ago.

If you reckon you can handle a fair amount of math - particularly matrices and vectors - then 3D shouldn''t be too hard to learn straight away.

If, however, you want to hone your skills on the other parts of game development - and actually get some simple, finished games under your belt - then 2D often has fewer complications.

Superpig
- saving pigs from untimely fates, and when he''s not doing that, runs The Binary Refinery.