Here is the full list of all 7 Project Lounge achievements.
As a host have 7 visitors in your Lounge.
Pick up an object for first time.
As a visitor spawn an item in someone else's Lounge.
Save your very first Lounge.
Press apply button at least once in Options Menu.
You launched the game at 1AM. Sure you shouldn't be sleeping?
Fall out of the Lounge... and go back to where you came from.