The Sims: Superstar adds over 250 items to the base game, including swimming tanks, massage tables, skydiving simulators, oxygen bars, mud baths, spa steamers and wall-mounted televisions. Sims can also purchase a satellite dish to unlock four new stations for their television: sports, animals, entertainment and news. New items added to the build mode allow players to create everything from spas, to studios, and posh Hollywood houses.
The game also adds new NPCs to the game, a new career track; 'Fame', a new sub-neighbourhood; Studio Town, and a soundtrack of new orchestral and trance tracks.
Any adult sim can visit Studio Town by picking up the phone and calling a cab, however the sim must visit Studio Town alone, and sims who are not on the Fame career track must pay 50 simoleons for the visit. Studio Town contains studios, spas, sushi bars and other facilities, and is comprised of nine lots. With the exception of Studio Town Center each lot is focused around either the modelling, voice recording or acting professions. The nine are lots are as follows:
- Buckingham Galleries
- Cameron's Lounge
- Fairchild Film Studios
- KWLW Studios
- Meeker Studios
- Music for the Eyes, Inc.
- The Gast District
- The Midlock Multiplex
- Studio Town Center
Fame Career Track
The Fame career track is very different from any of the career tracks that have appeared in other Sims games. There are no scheduled times or carpool for the career, and players control their sim at work at all times. To start the career track sims must hire an agent from a tabloid newspaper and when a player is ready for their sim to work they must instruct their sim to call a cab to take them to Studio Town. Once in Studio Town sims must interact with specific objects such as recording booths, movie sets and fashion runways to get paid. To interact with a career object in Studio Town sims need to be in a positive mood and with early objects the better a sim's mood, the more likely they are to succeed in using it. With objects used later on in the career track, players must play a menu-based mini-game to help their sims perform.
While there are job titles for each job in the career track, the game focuses more heavily around the 'starpower' of your sim, a 0-5 scale rating system that increases and decreases by 0.5 at a time. As a sim's starpower increases they gain the right to interact with new objects in Studio Town and the more starpower needed to interact with an object, the more a successful interaction with that object will pay. To increase their starpower sims not only need to increase their body, creativity and charisma skills but also need to make friends. Unlike in other career tracks a sim's job progress is only affected by how many friends they have personally, not how many friends their whole family has, and instead of promotion being based on how many friends they have, it is based on the combined starpower of all of their friends.
Sims can only find other NPC sims with starpower in Studio Town, which is populated by two types of sims: Somebodies and Anybodys. Anybodys are sims which are usually regarded as "the little people" or fans of people in Studio Town, while Somebodys are celebrities themselves. Anybodys have less starpower than Somebodys but befriending enough of them ensures your sim will not get a visit from the obsessed fan (see NPCs). Somebodys with stars above their heads are exceptionally famous sims which are very useful for sims to befriend, however it should be noted that their needs deteriorate faster than other sims and they are generally harder to interact with than most sims. Sims can also stage publicity stunts or pose for the paparazzi to help their career. Should a sim not visit Studio Town for two consecutive days their starpower will decrease.
With The Sims: Superstar installed when the paper girl drops of the regular newspaper outside your sim's house in the morning, they will also drop off a tabloid newspaper. Not only can this newspaper be used to read for fun and to hire an agent, it also shows players the top ten most famous people in the game. If players have The Sims: Makin' Magic installed it is possible for them to make the 'Price of Fame' charm, which if used when a sim has three or less stars will instantly catapult them to 4.5 stars, however if they use it when they have more than three stars it will cause several obsessed fans to appear. When on the Fame career track sims can also receive the Simmy Award for achieving high status as a celebrity, or the Sim Choice Award if they manage to attain a high relationship with the Anybodys of Studio Town.
The following is the list of job titles in the fame career track in the order they are encountered:
- Stepping Stone
- Name Dropper
- Studio Fly
- Sell Out
- Talk of the Town
In addition to the Somebodys and Anybodys of Studio Town, as well as the various people who help run Studio Town, The Sims: Superstar introduces a number of other notable NPCs. Butler
- The Butler costs 500 simoleons a day to hire and will work for a sim from 7 a.m. until 11 p.m. The butler will cook, clean, take care of pets (if The Sims: Unleashed is installed) and babies, garden, get rid of unwanted guests, and call the repairman should anything break. Celebrities
- A number of real-life celebrities made cameos in the game, including Avril Lavigne, Chrstina Aguilera, Marilyn Monroe, and Jon Bon Jovi. The celebrities wander around Studio Town, where sims can ask them for their autograph. Freddie Prinze Jr. can also be downloaded as a celebrity to the game, Marilyn Monroe takes on the secondary role of presenting your sim with the Simmy Award, and Andy Warhol can sometimes be seen as a cameraman. The Obsessed Fan
- Should a sim pay too little attention to the Anybodys of Studio Town while on the Fame career track they will be pestered by The Obsessed Fan. The fan will annoy sims, leave roses on their doorstep, rifle through their garbage, and steal their awards. Even when asked to leave the Obsessed Fan will return before long, the only real way for a sim to rid themselves of him is to establish a better relationship with some Anybodys.
- While almost all expansions for the original The Sims have similar counterparts for The Sims 2 and 3, there are no expansions for either game carrying the specific theme of The Sims: Superstar.
- The Obsessed Fan bears some physical resemblance to John Hinckley Jr. A man who stalked celebrity Jodie Foster and tried to assassinate President Ronald Reagan.
- The Studio Town production co-ordinator in The Sims: Superstar is called Lana. She bears resemblance through her name, appearance and role to Kana, the vacation director from The Sims: Vacation.