timgurto, sounds fairly intensive there...
im wandering are you doing sdd accelerated? coz if you not, dont choose a hard project that will take up lots of time, coz yur gonna also have to concentrate on other subjects for hsc. really basic projects are enough, just put lots of effort into the theory part of it.
i did a network/internet chat program, 5 pages of coding (java =D), took me 2 days to code it, 1 week to debug it, and i put heaps of effort into the theory part (documentation, etc), and i got 100 for it. initially i said i was going to make some full kick ass program, that would do like everything.. but then after a week i realised theres no point.
anyway, my friend, whos been programming c++ for a while (and is quite good at it), tried to make a 3d asteroids game. in the end, it had many errors, and he lost heaps of marks.
so just because your heaps good at programming, doesnt mean you need to create a full stratergy graphics game (game development is quite hard, im saying from experience as i hve made many games). and this is just my opinion, but games dont work in vb =p
ive seen many ppl waste a month just devoted to their major project, and they miss work in other subjects... not the way to go
i dunno if your teacher will let you guys do whatever u want, but if he/she does, go for something easier... more time is reqd on documentation (internal and external, incl help files, etc)
basically u dont have to challenge yourself in yr 12.. when simple things are enough... challenge yourself after u complete your hsc and have free time to do whatever you want =)