If you look at the (hundreds of) games in this topic, I'd guess that about half are 2D. That's for Unity iPhone, but it's basically the same as Unity. Except for the "free" part.
Unity is probably your best idea seriously follow this tutorial.
Just give it a little while to get used to using it, at first it can be scary with all the information that it gives you but to be honest you'll end up using only 10% of the tools and information likely.
Totally free, you even get a trial to the pro version. And unless you know a bit about programming then its a great way to start programming instead of jumping into SDL.