Unmechanical is a very simple maze/puzzle adventure game that I liked so much I ended up playing it twice. First run took me about 2.5 hours to complete. Second run took about 1 hour plus some extra time wrapping up the achievements I missed on the first run. So yes, this game can end up being really short. But if you don't take time to soak up the surroundings, the backgrounds, the atmosphere, and the music, you'll end up missing out on a lot.
Even though you essentially only have a single ability, the designers manage to offer several different environmental variables that make you use it in vastly different and clever ways. The game provided a charming appeal similar to Machinarium and was definitely worth my time.