Candy Crush Saga creator King Digital Entertainment (KING.DL) reported first-quarter earnings on Wednesday, and shares promptly dropped nearly 7%. King and Zynga (ZNGA) are the only publicly traded companies focused on social gaming. But Zynga might soon pursue a different business model, and King's future overly depends on the success of one title. Were King's first-quarter results sweet, or were they signs of an impending crush? 

King reported adjusted revenue of $608 million with $0.61 EPS. Year-over-year comparisons don't work well for this company because the numbers tie directly to the rise of Candy Crush. So, what were the key takeaways from King's first-quarter earnings release?

1. Candy dependency lessens
King revealed in its pre-IPO documents that Candy Crush accounted for 78% of total bookings, which created a dangerous dependency even in an industry known for dependency. Zynga, for example, tied 64% of its overall first-quarter online game revenue to three titles: Farmville 2, Zynga Poker, and Farmville. But King's situation improved in the first quarter.

Candy Crush Saga accounted for 67% of gross bookings even while bookings grew 1%, quarter on quarter, to $641 million. While Candy Crush was on the decline, Farm Heroes Saga stepped up to bridge the gap.  

2. Player growth is up
Candy Crush's popularity has faltered while bookings and revenue both grew only 1%, quarter on quarter. But did that money slowdown come from a drop in the player metrics of daily active users, or DAUs, and monthly active users, or MAUs? 

Source: Company filings 

DAUs were up 15% since the fourth quarter, and MAUs grew 18%. So why didn't bookings or revenue grow more? That answer is found in the monetization metrics. 

3. Monetization metrics fall
Monthly unique payers, or MUPs, refer to the number of players who make a game-related purchase during a month, with an average taken to get the quarterly result. King and Zynga both specialize in free-to-play games, so MUPs basically describes in-game purchases.  

Zynga's MUPs stabilized between the fourth and first quarters, with an increase of 5%, to 1.4 million. King's MUPs fell more than 2%, quarter on quarter, to 11.9 million.  

Source: Company filings 

Calculating MUPs as a percentage of another user metric -- monthly unique users, or MUUs -- provides the amount of players making purchases. King has historically sat at around 4%, while Zynga stays around 2%. 

King's first-quarter MUUs were 352 million. So King's number has dropped down to around 3%. That's still better than Zynga, so no need to sound that alarm quite yet. But it's worth following this metric in future quarterly releases. 

Foolish final thoughts
King's growth decelerated as Candy Crush Saga began its predictable slip in popularity. The company at least lessened how dependent it is on that one title, but that might not prove enough padding should Candy Crush's bookings plummet between quarters.