Zynga has announced that it will kill off 11 of its social games as part of a new cost-reduction plan that aims to improve its profitability. Many of the titles have already been closed and removed from app stores, while others will be shuttered in the coming weeks and months. PetVille, FishVille, and Mafia Wars 2 are three of the titles on the hit list.

Zynga has produced some hugely successful social games in recent years, but it’s also had a number of big flops that have cost the company dearly. Back in November, CEO Mark Pincus announced new cost-reduction plans that the company must implement in an effort to turn itself around. Part of those plans include staff layoffs and studio closures, plus the closure of 13 titles.

11 of those titles have now been confirmed. Some have already been killed off, while others have stopped accepting new players and will be closed later on. The titles are:

• PetVille — Shut down December 30
  
• Mafia Wars 2 — Shut down December 30
• FishVille — Shut down December 5
• Vampire Wars — Shut down December 5
• Treasure Isle — Shut down December 5
• Indiana Jones Adventure World — No longer accepting new players, shuts down January 14
• Mafia Wars Shakedown — Removed from app stores
  
• ForestVille — Removed from app stores
• Montopia — Shut down December 21
• Mojitomo — Removed from app stores
• Word Scramble Challenge — Removed from app stores

Zynga explains that with these titles closed, the company can use its resources to focus on other, more popular titles, as well as creating new games.

If you’ve never played these titles, their death isn’t likely to trouble you. But there are gamers who have spent countless hours and indeed plenty of money on these releases and will be upset to see them gone. TechCrunch reports that some have taken to Zynga’s shutdown notices to complain about the decision.

One PetVille player writes:

“Please don’t remove petville. I been playing for 4 yrs. and I’M going to miss my pet Jaime….why do you want cause depression for me and others. Why do you want to kill my pet?”

In an effort to ease the pain, Zynga has offered those who played FishVille, Adventure World, and some other titles a free bonus package of virtual goodies in one of its more popular titles, including CastleVille, ChefVille, FarmVille 2, Mafia Wars, and YoVille.

• ViaTechCrunch