I must say it doesn't help having fanatic quotes in our signatures or avatars (ahem Elysia, you ooze C++ fanboi). Then we got people here who exclusively use C, or C++, but never both. Personally, not only do I see both their merit, but would consider both as options for projects until omitted. Many people here will just jump straight to one language. Fanaticism, fanboyism, whatever you want to call it.
All I meant was don't be a masochist, like that guy in in the job section developing Wagrold. Don't go and start reading NeHe thinking you're going to code some custom graphics engine. There's really no purpose unless you plan on making that a career choice (3d engine developer). Even then I'd probably start at a higher level. There's really nothing wrong with C for this project other than libraries. Your project will never be scaled higher than many successful C games, such as open sourced Quake 3. Nowadays you're going to want the options C++ provide for games. There's a good chance you'll just end up writing C with classes style code anyway (meaning you don't fully understand how to utilize C++, which takes time, and the further you go along the more you favor metaprogramming over OO). You could always just ignore templates or classes, or both, if the style fits you better. In many cases I don't see any reason to go fully down to C for games, applications, etc.
If I were just starting, I would be looking into the recently released
Unreal Development Kit, or the good ol
Source Engine. Start at a high level. Actually achieve something. Start a team or join a team (there's plenty ranging from mods, to professional). If you disagree, well, revert back to previous suggestions.