Schemaverse isn't nearly as polished as this is but if you are looking to battle some AI, give it a chance.
That would be a really fun game mode! It would require a lot of thinking about game mechanics and the technical challenges involved, but it's definitely possible, but probably not in the immediate future. I think if we implemented features like a resource system and figured out how to make the game performant, a persistent MMO would be really entertaining, something like coding the AI to a long-running Starcraft game.
It'll be hard, but not as hard as what we've already done with sandboxing and live-coding user programs, and it'll be truly epic.
I'm thinking about the mobile one, for example -- since the commands players use are limited to an API, could a drag-n-drop interface for that API work? Then the only things actually requiring typing would be function arguments.
I'm not a kid anymore, but I want to act like one.
Then this turns into Clash of Clans. =)
These types of games are really interesting and having this one available in the browser gives it a significant advantage over others such as http://aisandbox.com/ which when tried was a little too complicated to setup for casual usage.
Reminds a bit of my darker days working with Macroquest.