A while ago I played a similar online game with these lads, where the aim is to discover clues, tools, bits of puzzles etc to achieve a solution - be it a collection of pearls or in this case an escape from a room: Christmas Escape.
The player has been locked in a room for wrecking previous Christmas parties; my kind of role!
As a stand alone, this is intriguing but language free (mostly - the odd note here & there) and a lot of random clicking around a scene. Not much point for an English class then!
The trick is to find the relevant "walk through" or solution on eg YouTube. If you have two computers great, if only one, then open up the walk through in a separate tab.
The rule is simple; the helper cannot touch/point/narrate; has to guide their partner with instructions/directions/explanations. Lots of language there! After 5 mins, guide & player swap roles. Teacher can monitor & help out with key phrases - suggest making a list on the board as the need arises.
A lot of these kinds of puzzles are long & involved; find a fairly short one that can be solved in the time available.
A couple of ideas to follow up; use something like Jing to record your own walk through with commentary. Alternatively, write down the directions - or a section; with multiple groups assign parts of the story to each.