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