problem with a game

hey. I have a problem. I’m making a game. In the game the camera keeps going thru the walls. help me please. oh and by the way when this game is ready i will let you guys know. and when i get it ready will i be able to turn it into a exe file or sth that everybody can play it not just the people who have blender. plz help.

You can place an empty at the position of the camera and parent it to the camera.
Via a collision detector it should be possible to prevent the empty and also the camera to move through the walls.

But I think you should ask this question in the “Game Engine” forum. The people there can help you better.