@ChronotriggerJM
I agree that you and me could make a game which is over 150 megs... so its not the size that matters. Xbox live arcade was meant to have a retro feel. It is not supposed to compete with normal xbox games. Also it is not meant for independent developers to express their creativity and imagination...thats what XNA games will be for.
You will notice that about 50% of the games there are shooters and another 30% are old console and arcade ports. The last 20% are tetris like games. There are only a few games that stick out from that pattern...(My avatar for one) Its an old school arcade...
The best way to control this and make sure companies follow the same idea is to control the game size and review larger games on case by case basis. there is not much you can do with 150 megs in HD and with surround sound...other than those games listed above.
The reason that PSN doesn't have similar size limit amongst other things is because of a serious lack of vision of what their live service offers and where it offers it.







