Warehouse on Blacks St (Challenge) -Wake Up for The Last Time-

I feel really tempted to make a guy who is the one that locked them all in the warehouse and the one who kills them, gives them the tasks, etc. I can just picture him surrounded by computers with a coffee in his hand just watching them all while they try to escape. I'll probably put him on the second level. Which brings me to my question; can we have basements and other levels or do we have to have it all on the ground level??? :)

Btw; I really like the look of this challenge. I'll have a lot of fun with this! :D