The beta is available from the Steam library game properties "Betas" dialogue, branch "16_update14version_rc".
with regards to the previous Beta:
changes
- meadow grows smoothly when meadow size changed
- flower density increased
- when more than 3 logical cores are available weather calculations are performed looped across every of those other cores
fixes
- key for turning left not working when a joystick is connected and not actuated false values might be delivered by the game engine resulting in unintended movement until the joystick is touched briefly