Snapshots are untested versions of Chunky released sporadically in order to get feedback on upcoming features. You may choose to use snapshot versions by selecting the "Download snapshots" check-box in the Chunky Launcher:
After enabling snapshot downloads you may check if there is a snapshot available by clicking the "Check for Update" button. If a new snapshot is available you will see the "Update Available!" dialog.
It is not uncommon that the snapshots contain critical bugs. Please backup your scenes in order to avoid losing important data!
Scenes created using snapshot versions of Chunky may be incompatible with other versions of Chunky, even later proper releases!