"Britney Spears: American Dream" is the latest attempt to convert pop culture fandom into mobile game sales, but the trend is likely to produce diminishing returns for mobile developer Glu Mobile. In the game, released last week, players start out way down on the E-list, but Britney is there to serve as a mentor and an important connection to bigwigs in their quest for musical superstardom.

Choosing clothes, cutting singles, performing with Britney and confronting rival singers are just a few things players can expect from "American Dream" — if they don't mind waiting around.

Players begin by customizing their avatar. They can also earn currency, B-Gems or energy by completing different objectives or climbing the celebrity ladder. Sometimes clicking around the screen can lead to some additional cash. Networking leads to more contacts, who will help boost performances and appearances. And of course, this being pop music, there are romantic interests as well. 

Completing each event in the game requires spending "energy" to fill up a meter. Say you're cutting "Lonesome Trucker Blues," your first country single. You can add additional musicians to boost the rewards received by completing different objectives during the event. Performing a guitar solo may require five energy points, while adding hand claps costs two. The actions requiring more energy will provide greater experience and fill up the meter faster than lower-energy actions.

With a limited amount of energy, players must either wait for their energy to replenish — one energy point every five minutes — or purchase energy to continue. In that sense, "American Dream" follows the in-app purchase revenue model that has proved lucrative for game developers. 

In fact, through every event in "American Dream," there is much waiting if you don't want to spend money. At times, you have to wait for a call to unlock the next event. Every scene also requires some time to load, which adds to the sluggish gameplay. Another drawback is the required network connection that limits where you can play the game  if you don't want to use up your data. 

Glu Mobile struck gold in 2014 with "Kim Kardashian: Hollywood." The celebrity mobile game appealed to casual players and those who couldn't get enough of "Keeping Up With the Kardashians." When "Hollywood" debuted, it was one of the top-five-grossing apps overall in the U.S. among iOS devices, according to App Annie.

But even after that hot start, retention issues became apparent: Players did not stick around, with the audience dropping drastically by winter. "Kim Kardashian: Hollywood" failed to reach the $200 million in sales predicted by analysts. To date, it has earned just over $100 million since its June 2014 release.

"Katy Perry Pop," the next celebrity game released by Glu, debuted outside of the top-100-grossing iOS apps. The game never found an audience and quickly fell out of the top-grossing list. It was a disappointment that highlighted the uncertainty of celebrity games as a mobile genre. Hoping to get back on track, Glu tapped Kylie and Kendall Jenner for its next mobile game. "Kendall & Kylie" let players take photos, customize them with stickers and start their career in fashion or media.

The massive social influence of the Jenner sisters failed to translate into a truly engaged audience for the game. "Kendall & Kylie" was among the top-10-grossing iOS apps when it was released in February but soon dropped to among the top 40 list. As of Monday, it was the 174th-highest-grossing iOS app.

Even if "Britney Spears: American Dream" is not the hit Glu is hoping for, the trend of celebrity games doesn't seem to be letting up: Nicki Minaj will have a game released in 2016. And if all else fails, there's Taylor Swift, who has her own game scheduled to launch this year.