Restarting the game is already possible, by clicking "respawn" in the top right menu.

I had a similar problem, however, I think the problem is simply:
"Sometimes placing your Spawn does not happen."

I had the problem when I wanted to respawn (and I can reproduce it that way):

• Go to menu, respawn
• go to the room you were in
• wait until the timer is finished
• click on a valid location
• you get a popup which asks for the name
• click "spawn"

Nothing happens...

• click on the same location
• the popup asks you for the name again
• click "spawn"

Your spawn gets placed.

I have/had similar problems with lookForAt. Strangely, it does seem to work when using the different method header.

room.lookForAt('creep', 10, 10) <- does not return the correct information
room.lookForAt('creep', room.getPositionAt(10,10)) <- seems to returns the creep correctly...