Where is there a free virtual game for free like roblox?

There is another game like Roblox, with better graphics. Its called Blockland. Even though the demo is free to download, there are some restrictions, that prevent you from playing on an online server (with other people) The full version is $20, with no monthly fees, but that would get rid of the "free" part of your Question. So yes the demo for Blockland is free.