I know that C:BFD is parodying movies, making it a parody game, and A & O while also being a parody game is parodying games. I don't see it so much as stealing other games deas, I think its more them just making fun of the other games.
Nintendo was soo sure that someone would steal their water pack idea...... Now they did, with Mario look-alike included. I'm sure its a bunch of themed areas, like Conker, that would use the look (and feel?) of many well known games to make not just make fun of those games, but also (hopefully) to mak a fun game that is all of your favorite games (in spirit)
I don't know much about the game but it already looks like fun, and if I owned a PS2 i would probably get/rent this game.