Any game that offers less than 1 hour of entertainment should probably be free, in my opinion. The way you describe it, it almost sounds like a demo or proof-of-concept rather than a finished product.
I got the same impression from it. A full length sequel or something like that could actually work, and if it maintained the same mechanics, I'd be on board.
The only thing my milkshake brings to the yard is a subpoena.