Here is the full list of all 7 Project Lounge achievements.
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.
Pick up an object for first time.
As a visitor spawn an item in someone else's Lounge.
As a host have 7 visitors in your Lounge.
Press apply button at least once in Options Menu.
Save your very first Lounge.