It would be nice if you could invite specific players to play your level so that the invited player could comment on the level privately so that only you know what their opinion is on the level.
This would help to test out the new level and help to identify any improvements and good features in the level. Maybe this button can be found on the other player's profile. When pressed, the buttons opens up a list of your levels. A level is selected then sent of as an invitation to that player to play and comment on (or rate) @Barb @Seppo @wempu
What do you think?