Can someone mod the game and add more levels and more bosses?
Yeah, probably. I've been hoping for some Avenger themed level packs
possible? probably. likely? depends. you have to remember that games are made by anywhere between 30 to 100 people, that work 40-60 hours a week doing this stuff. i think it would probably take awhile, or a concentrated group effort. the biggest problem is lack of coding knowledge. there was an attempt to get the xml2 maps into the game, but i don't know how far that went.