All you need to play this game is a mouse or any similar rodent (though a capybara may be too large to use efficiently). Items are used automatically, if you have them, and you can click on the scroll to see what you currently need to accomplish.
The controls are really very simple, but remember: it's the journey that counts, not the destination. Take your time. Explore. Examine the details. Enjoy your time in the Mountains of Oddness.