As the Facebook games ecosystem continues to grow and diversify in 2013, we've seen strong performance from international game developers based out of Europe, the rise of cross-platform games on both web and mobile, and breakout hardcore game hits. Join us as we celebrate Facebook’s 2013 games of the year.

A few highlights from this year’s list of games. Out of a total 23 games:

• 10 come from studios based in Europe or the Middle East
• 8 are cross-platform, integrating with Facebook on web and mobile
• 8 were developed by indie studios
• 7 are mid or hardcore games
• 5 are arcade games
• 5 are casino or slots games

Morris said along with seeing more genres, he's seeing people playing games for longer periods, describing what he sees as "usage resembling core PC gameplay." He also said the biggest upticks for Facebook's gaming are in the evening during "prime time hours."

"It's interesting that play is peaking in the evening when all those other entertainment opportunities are available," Morris said. "Evenings are a precious time, when other obligations are behind you. Gamers aren't just spending 15 minutes during the day to while away the time at work."

Morris highlighted the five genres he's seeing expand rapidly at Facebook. Although he and Facebook declined to provide stats for each game's users or money earned through monetization, he said that revenue was up 18% year-over-year from the third quarter of 2012 to 2013.

1. Social Casino — This genre covers social versions of popular casino activities, where you play for in-game currency. Facebook highlighted examples like DoubleU Casino and Heart of Vegas as frontrunners in the genre, which Morris said is "very diverse."

"We have very big partners that were already big in the world of casinos bringing in successful IP from the real world, but we also have wacky startups on Europe with no experience," Morris said.

2. Match 3 — The influence of Candy Crush Saga in this puzzle genre is impossible to ignore this year, though this genre isn't exactly new to Facebook. This style of puzzle game has been endlessly reinvented for two decades. Other examples Facebook highlighted were Jelly Splash and King'sFarm Heroes Saga.

3. Hidden Object — Hidden object games involve asking players to hunt down objects in a scene. Morris said Facebook's huge stand out in this genre is Criminal Case, which the company named its "Game of 2013." Developer Pretty Simple recently said the game has 100 million players.

"I'm continually impressed with how diverse the player base is," Morris said. "It's a more diverse age range than you might expect."

4. Hardcore Simulation Games — Morris- pointed out that Top Eleven Be a Football Manager is one of the year's biggest successes, with 10 million players.

"It's playing in a space that we thought was core genre. You aren't playing soccer; it's a thinking, strategic game," he said.

5. Hardcore Strategy Games — Strategy games are mostly commonly associated with the PC. Morris said Kixeye's War Commander is a strong example of a real-time strategy game that requires deeply committed play. Other noteworthy strategy games Facebook chose to highlight includeWartune, King's Bounty: Legions and Soldiers Inc.

"The last 18 months show us that a company of almost any size can have a tremendous commercial success in a lot of different genres. Companies are really coming at genres from unique angles," Morris said.