I haven't been keeping a VERY close eye on this thread, so any repeat suggestions I apoligise for.
I was thinking last night and came up with some ideas:
1) How about 'cut-scene' support, I was thinking that when the PC editor comes out you might think of having the ability to convert animated gifs into gigas-compatible mini cutscenes.
2) I know that Gigas is meant for non-coders but a little scripting ability could go a long way, for instance a simple 'if then else' loop could be used to determine a characters reputation which in turn could determine how other npc's react to you. Or something like that, i'm sure other people have even more imaginative ideas.
3) music (!). Well, obviously really!
4) Support for projectile weapons would be nice, maybe even have them able to trigger certain hotspots?
5) Secondary items such as lanterns that can be equipped at the same time as your main weapon and used with B maybe.
6) talking, obviously
7) I had an interesting thought last night, perhaps you could incoporate gamma control into the game through hotspots. This would be quite cool, because then you could control night and day and light and dark rooms.
Thats all I could think of for now, well done so far Gigas is looking veeeerryy promising.
[edit] longest post I ever made