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)