Game for Science is a virtual world where students can create an avatar and explore various virtual islands with activities based in "health, aeronautics, genomics, environment, engineering and more." Students can visit the Virtual World as a tourist, or sign up to edit their avatar, chat with other players, and save their progress. Signing up is free, however, students will need an email to sign up and confirm their email. Visiting as a tourist, students do not need an email or to sign up.
I am a fan of open world online gaming cause they can teach our students many of the unwritten social rules about communicating effectively, respectfully, and efficiently online. Plus, my students love simply seeing other students in the virtual world they can interact with.
I would only recommend Games for Science as a fun extension to your classroom Science curriculum, and at home activity your students interested in Science could interact with, or as an activity students can experience when they are finished with a classroom project (as I am using in class).
Here is a video to show you more about Game for Science
As my students finish up and prepare for their Historical Figure Presentations, I am allowing them to check out Game for Science as an alternate activity when their work is complete.
Check it out at http://www.gameforscience.ca/