This hack was really fun to play through and I really enjoyed it. The only thing I can say is that some levels (like the first level) seemed a little bit empty, but since it's just a demo, it's understandable.
It's a short demo however given the nature of this hack and having to keep moving and collecting Time Clocks its understandable.
Like certain levels in Mario Galaxy and 3D Land + World you'll need to collect clocks in order to have enough time to finish the levels.
It's pretty good and I'd like to see the concept expanded on further. Maybe levels were you have a lot of time but clocks actually take it away would be interesting?