The Sims Olympus was going to be an online version, similar to The Sims Online, of what is now known as The Sims 4 planned after The Sims 3's success. Development was started in 2008, but it was canceled and The Sims 4 was released instead. The reason for the cancellation could be the critical reception from SimCity in 2013. The aesthetics and many objects from Olympus were reused in The Sims 4 base game, and a Tudor-styled world that can be seen in some screenshots shows resemblance to The Sims 4: Get Together's world Windenburg.
Olympus' signature feature was that Sims of other players could be identified by a blue Plumbob over their heads. In addition to that, the player would only be able to control one Sim at a time instead of an entire family unlike previous games. There's also a Plumbob statue in The Sims 3: University Life titled "Into the Future" referencing the blue Plumbob and The Sims Olympus project. The blue Plumbob concept was later used in The Sims Mobile to represent other player's Sims.
Leaked Images
These images have all been leaked on the internet by various developers that worked on Olympus.
Game Interface
Sims
Neighborhoods
Multiple screenshots of Olympus' neighborhoods can be found in the game files of The Sims 4. Some of the screenshots show a Tudor-styled world similar to The Sims 4: Get Together's Windenburg.