I know this is not related to publishing, but more to the user, and also the publisher experience on OVI.
You download a game (or application), download fails. This may happen because of connections problems with the mobile network, no more on OVI than on webpages, in my case it is always temporary. So if download fails, most likely you try again and it works.
Now the issue is: I've noticed that you can write a review after download has failed. Some users are going to be angry, write a comment "Can't download. Cr*p!", and give one star. They may try again later, then it works, they may even love the game, but the damage is done, they will not be able to replace their comment.
I know it's not that terrible, but look at any game, there's a substantial proportion of comments of this type. If indeed download is failing systematically (which I've never experienced on any product), there could be an easy way for the user to let know OVI, but please, do not allow to write comments when the game has not even been installed, and the problem (most likely temporary) has nothing to do with the game. It doesn't help anyone, neither users nor the publisher.