The latest update on the beta/testing branch includes an experimental sandbox mode, which has been requested many times.

Features:

• no monster attacks at night
  
• can play an entire year (365 days) - visual season changes may or may not work
  
• achievements, stats and leaderboards are disabled
  
• new peasants will settle in empty houses (though it may take a few days - basically, 50% chance per empty home every morning that a new family settles in)
  

Known Bugs:

• loading a sandbox map is broken (no buildings are loaded)