I know it is probably kinda odd to ask a question like this here but still, seeing as the community is made of a bunch of cool guys with different skills I figured: hell, why not. It certainly doesn't hurt to try.
So, anyway. Me and a bunch of my mates have just finished our bachelors in IT, working on masters at the moment but the problem is it's mainly boring stuff, business apps, that kind of crap. We wanted to try something fresh, that would be both fun and educational and so here the comes an idea of a (how surprising!) game.
I don't want to know "how" since we are all programmers (more or less), I would like to hear your suggestions about the tools/frameworks that could possibly be used to build something like this. The obvious answer seems to be C++/DX but meh, we wanted something different. We thought about XNA/C# and if nothing new comes up we'll probably stick with that.
The point is, since the game will be strictly 2d and we want some online components in, I thought that there might be something there that does not use DX at all. I just don't know what, since I've wasted most of my IT life at coding stupid banking systems or some other B2B nonsense. Adobe Air comes to mind, maybe? Maybe something else?
I would greatly appreciate any suggestions if you have any. Also, excuse my pathetic English, I am a bit tired today.

Well, Adobe Flash is the most common choice for 2D games that are platform independent. It comes at a premium though and might not be the ideal choice if this is just something to do in your spare time.
Java is another option and is similar to C++ so you might not have too much bother picking it up. It's platform agnostic also.
I don't know if Construct would be of any help. It's free.

How about using C++ and programming for DOS!? Well DOSBox. I always thought DOS graphics programming was a lot of fun. Then you could also have proper multiplayer. I'm talking null modems and hotseats baby!
I'll go back to my corner now.

That depends a lot on how you define "platform independent". If you want to target smartphones and handhelds, then Flash is out.
SDL is widely used in non-commercial multiplatform games, I believe, with the coding itself usually done in C++.

Especially the iPad. :P

The iPad isn't a platform, it's a paperweight ;-)

True that. :D

The nice part about XNA is that it allows you to easily port your game to the Xbox and handles a lot of things well (Flotilla was made using that and is a great little game). Combine it with a great (imo) programming language (C# that is) it makes for fun things.
Also, I always considered it to be better to have a challenge/build something overkill while learning than to have to do it while actually being paid to.

i'd go for either pygame or xna.

Aye, I really like C# and that's why I was trying to find something that uses it. So far XNA looks the best. I checked that Unity thingy and it sounds neat and from what I understand it can use C# for scripting as well.
Does anyone know anything more about it? I read everything that's written on their website but I am still curious.

I think you should start from here on Unity.

unity is mono, which rules out some tutorials. last time i checked mono is not 100% compatible with the .NET standard.

Okay, after some thought and reading I decided I'll follow my tradition of being a Microsoft Nazi and we'll try XNA/C#.
Thank you so much for all your help guys!
edit: Oh and btw. do you guys know if XNA 3.1 works with Visual 2010? My laptop is freshly formatted and I can get either Visual 2008 and 2010 from MSDN.