That list is fairly similar to mine -- html, php, (not much) java, BBC BASIC, qbasic, vbasic, c, c++
have you done *any* work in c? if not , no matter, you can just go to one of the many tutorial sites on the net. I have a couple of ground rules with the adventure game engine though -- We will not be using DirectX (well, sort of). We will be using a library called SDL (
http://www.libsdl.org) which is a cross-platform (linux, windows, mac) way of doing graphics/sound/input. In windows, it does output to DirectX, but we don't need to access it directly.
Actually, thats the only ground rule i can think of... :)
I'll contact you when I have a fair idea of how the project will be structured and development can start (The first decision is whether to use C or C++...)