The meaning "get up to" in context

Question

— How did architect become involved?
— Well, someone had to design the dreams, right?
— Why don't you give us another five minutes?
— Five minutes? What--? We were talking for at least an hour.
— In a dream, your mind functions more quickly... therefore time seems to feel slower.
— Five minutes in the real world gives you an hour in a dream.
— Why don't you see what you can get up to in five minutes.

I've found the meaning of get up to here but I can't understand how it can be bounded with that context?

Answer 1

This looks like a transcription of dialog from the movie Inception.

In this case, it may help you to look at the original script:

Ariadne: How did architects become involved?
Cobb: Someone had to design the dreams.
(to Arthur) Let’s go another five minutes—
Ariadne: We were only asleep for five minutes? We talked for an hour at least. . .
Cobb: When you dream, your mind functions more quickly, so time seems to pass more slowly.
Arthur: Five minutes in the real world gives you an hour in a dream.
Cobb: Why don't you see how much trouble you can cause in five minutes.
_{Source: Movie script - Inception (2010) [.pdf], hosted by the Drexel Screenplay Library}

Answer 2

The definition of "get up to" from the MacMillan dictionary might be more helpful:

to do something, especially something that you should not do

In the context, it seems like the person is saying "I'll give you five real world minutes. Why don't you go see how much mischief you could cause in a dream during that time?"