It is dark, but not hopeless, and was successful in its day in Europe and the United States. It was first translated into English in 1923 but a more accurate 1990 translation in English is available in Towards the Radical Center, published by Catbird Press.
Note: The title of the play is actually R.U.R. (Rossum's Universal Robots). The heading of this page is inaccurate. I'm new to Wikipedia & don't know how to change the heading, or what effect that will have on pages that might link to this one.