An attendee tries out a Electronic Arts video game during the annual Studio Showcase media event at the company's headquarters in Redwood City, California.

Electronics Arts has "a lot to prove" between slowing sales of the latest iteration of best-selling soccer franchise FIFA and a host of mixed-reviewed games like "Need for Speed," according to one Wall Street brokerage.

Jefferies analyst Timothy O'Shea downgraded shares of the video game maker to hold from buy Thursday and warned clients that EA's 2019 content lineup remains largely untested.

"Non-sports games is precisely the area where EA has the most to prove," O'Shea wrote. "Excluding sports games, EA has launched a string of misses. Mass Effect Andromeda got a 71 metacritic. Need for Speed got a 62 metacritic rating. And Star Wars Battlefront 2 saw a massive fan backlash."

The company — and its investors — hasn't had too much to worry about in recent years thanks to the success of FIFA Ultimate Team, the latest chapter of what's become one of the most popular sports video game series in history. Ultimate Team, which allows gamers build up a dream team, is EA's highest-margin business, generating sales through virtual goods, the analyst said.

Such purchases, though, have proven to be a heated topic among EA customers and across its games.

When EA introduced the in-game moneymaking strategy in "Star Wars Battlefront II," hoards of angry gamers took to social media and Reddit to berate the decision, arguing that the game was structured as "pay to win."

The uproar centered around loot boxes in the title's in-game purchases system. Such boxes allowed players to save time by shelling out real money to accelerate the "unlock" of major characters such as Darth Vader. Due to the negative sentiment, the company was forced to turn off all in-game purchases a day before the title's official Nov. 17 launch day.

"When EA brought loot boxes to Star Wars Battlefront 2, the fan backlash was swift and severe," O'Shea added. "Battlefront 2 dramatically underperformed its original estimates, and bowing to pressure EA capitulated to gamers by removing loot boxes from the game. This was a first important sign that Ultimate Team growth would begin to stall."

The analyst cut his price target on EA shares to $95 from $139, implying just 5 percent upside.