BETA (Early Access) version contains:
Huge extension for Level 0
New sublevel system with two new sublevels: Art Gallery and Forest
Huge extension for Level Office
Two Endings!
Many new paths and open-worldish system of levels
2 New entities
Multiplayer up to 6 players
VOIP
Achievements
New languages - German and Japanese
Player movement overhaul
New weather system for start level