Tips for adventure making.

I'd say that it's less about the exact length of an update, and more about how much happens in it - i.e. you should aim to keep the pacing of your story consistent, and how many words you use to achieve that is your personal preference. Some readers like it when you ask for their input after each action, others want to see the story advance quicker and in larger steps. Pleasing both probably won't work very well in the long run, so pick a pace you're comfortable with.