It's basically minecraft, except its different.
www.cubelands.comFeatures (copied straight from the website)
Platform: Playable on Mac and windows (Online or via standalone program). Dedicated servers: Mac and Windows
Free: Cubelands is free to play, but if you buy the game(Premium) you unlock many extra options.
Multiplayer: Play with 16+ friends simultaneously (Todo: We need to test the max.)
Freedom: Build whatever you want
Social gaming: Share your creations, feel free to brag.
Upload screenshots to your online profile from within the game
Online player profile: Achievements, statistics, screenshots, messaging
Community support: Make friends in the in-game chat and compete against them and many others in the community competitions
Many more: Since Cubelands is pretty open ended there's room for your own imagnations! Like roleplaying? Start your own castle
Buy the game: Safe & secure ordering. Temporary development rebate of +-25% (7,50 euros instead of 14,99 Euros)
Its a closed beta, but put in your email and you may get an invite.